This seems to happen every single year. Somewhere in the time between the Autumn releases of the large sets, the cards that were seemingly free, abundant and endless quickly become rarities with real, tangible costs. The cards that were once left behind after a booster draft are now selling for more than pocket change, and somewhere along the line, you realized you're fresh out of them all. It seems to happen every single year, and I have no idea why so many people get left behind.
Actually, I do. It's because most people are short-sighted when it comes to trading. This usually manifests itself in an attitude of "it's just a game", but anyone who knows me knows that a game is never just a game. It's an opportunity to excel and learn. The people who claim that they only trade for what they need are missing a myriad of opportunities in which they could easily trade-up while acquiring more "liquid" cards. Regardless, I respect their position, since it's a lot of work keeping up with all the prices. If you're a trader who only trades for what he needs, this article is probably not for you, but if you're willing to think more than one step ahead when dealing then there might yet be hope!
There's a point at which an uncommon, and specifically an uncommon, goes from affordable to inflated. I judge "inflation" by the reactions of customers; when people find out that Sensei's Divining Top is over $5, they flip. Same goes for Bloodbraid Elf in her prime, Path to Exile as well. The majority of uncommons don't ever reach that level, but some may be primed to hit the $1+ mark. Looking at the past, we can see that uncommon land cycles were expensive. There were some clear tournament staples as well, and the most expensive ones came from the short-run sets (Eventide, Alara Reborn, Rise of the Eldrazi...) That said, let's find a few that might still be easy to acquire.
Rise of the Eldrazi
Joraga Treespeaker - Already going for $1+ in many places, this is the kind of card you will randomly get 20 of when you pick up a collection or bulk lot. Cards like this make buying recent bulk a dream, since each playset will more than pay for 1000 cards if your prices are correct. It's inclusion in ROE only further assists the value, since ROE was only drafted for a short period of time and was a larger set. Flores, Chapin and others have been crowing about the green Sol Ring (don't believe me? Draft one in the cube and get back to me), and oh yeah, Elves is a dominant beatdown deck thanks to Ezuri, Renegade Badass. I can see Treespeaker being a pivotal card in the format and if so, will easily command $2+.
Wall of Omens - When I was you're age, this card was called Wall of Blossoms and it was green. That didn't keep it from being worth more than most of the rares in Stronghold. Now is an awesome time to snag these, since Black is the new White today. Wall of Omens might not drop in dealer price, where it's around $2 already, but the tournament players who follow the trends might be willing to part with theirs cheaper. Encourage this and reap the rewards, since this card is a power uncommon and will be for years to come.
Dreamstone Hedron - I have had this 3x Mind Stone on my radar since Day 1, and it's yet to do anything. The ability to ramp from 6 to 9 is insane when 10+ mana gets you Eldrazi, and in a ramp deck, a 3-for-1 is a 3-for-1, even if it costs 9 mana. Sometimes the extra cards are all you need to make a final push. I see this alongside Koth, Mox Opal, Chalice, and Voltaic Key to make a mono-red Wildfire style deck. It's no Thran Dynamo, but then again, Thran Dynamo didn't have an Ancestral Recall in the trunk. The Dreamstone Hedrons are practically free in trade, and can probably be had with minimal effort. Though they may never command a huge premium, it would surprise me if they never found a home. Low risk, high reward.
Enclave Cryptologist - A looter that turns into an Archivist might have been a rare back in the day, but these days, it's a lowly uncommon. It's not hard to abuse a 1-drop Blue creature between Ranger of Eos in Extended (remember that format? it's coming back in January...) and Grand Architect in Standard. This is another card that dealers sell for a good amount, but most players don't much care. I cannot say how often I receive these as part of "bulk" cards, but I will simply say that it's more than enough. The card is fantastic, and should see play in a variety of decks. It's also got mild casual appeal.
Forked Bolt - Elves hate lightning. They hate it even more when it can pick off their best Lord or 2 of their un-augmented dorks. Between this and Arc Trail, Elves are in trouble. Don't get me started on how hard Chain Reaction wrecks those little green morons. Rant aside, Forked Bolt is one of the most powerful and versatile 1-drop burn spells we have. Nothing beats the raw killing power of Flame Slash, but being able to 2-for-1 the right deck is more than enough to justify its inclusion in any anti-weenie strategy. Forked Bolt is the kind of Uncommon you long for on the day of the event. You know the card would be perfect for your board, but no one brought them to the event. The dealers are out entirely. And your 5 playsets in your backpack? Worth whatever you want. Just keep 'em on hand and thank me when you randomly quadruple your money.
Inquisition of Kozilek - Not cheap dealerwise, but you will often find these in a 25c box, the back of a binder, on a draft reject pile or otherwise nearly free. Some players realize that the card is powerful, yet lacking a true home, and as such do not discard them so quickly, but many will throw these in for virtually nothing. I'm not an Eternal player, but I think this card complements a Duress-based strategy pretty well. I can certainly see it's value against a deck like Zoo, where the combination of nuking a Tarmogoyf and knowing their hand is a massive advantage. This is one of those uncommons that, in 5 years, you'll realize you wish you still had.
Survival Cache - I love this card in the right deck. White is not supposed to get such a powerful ability. It's not too hard to ensure you're the guy with the higher life total; you have the new Soul Warden clone, Rest for the Weary, and multiple playable creatures that reward you for gaining life. In this deck, drawing 2 cards and gaining 4 life is about as good as it gets. Conley's deck won't be a direct port to Standard, but I'm sure the basic engine can be reapplied to new strategies. I routinely run low on them in the store, but it never feels like there's a "run" on the card. I'd rather have a ton of them that never move than none when I have a ton of orders for them. They're easy to get.
Worldwake
Cunning Sparkmage - He hasn't seen a lot of play lately, and I'm not sure why. A hasted Pinger existing in a format with Basilisk Collar can really change games, but the Sparkmage is getting no tournament love nor any respect for its market price. That's fine, because no one ever won a championship by paying retail on under-rated commodities. Stock up while they're still out of vogue and get paid off when the Hive Mind figures out that this card is still good.
Everflowing Chalice - I told everyone I knew to buy as many of these as they could about 2 months ago. Glad to see I was right. These could be had for 25c a pop up until recently, and now a playset could set you back $5 or more. Making $4 on my $1 agrees with me, and I'm sure it agrees with you too. Some people may not know or care that these are starting to dry up, so hunt them down like a hawk. This is one of the most important cards of the era and will see play across formats eventually. If this happens, $1 might look cheap for this amazing mana accelerator.
Kor Firewalker - The buzz around Kor Firewalker has died down a bit, and there's not much more to say about it. It's really good at beating a specific deck, so its popularity waxes and wanes routinely. If you can source a bunch while they're down, you might be able to make a quick buck when Red Deck Wins players start getting too dominant.
Loam Lion - Despite not seeing any play in Standard, these have seen Legacy play. Judging by the fact that I once traded a foil Loam Lion at like $6+, I'm surprised to see they're still fairly cheap and easy to get. Worldwake was drafted so infrequently compared to the other middle sets, so it will eventually become scarce. That's when it'll be great to have a stockpile.
Tectonic Edge - The fact that I can sell them for almost $2 each, all day long, should tell you how good this card is. Sun Titan turns it into something nasty, and it has a long pedigree of killing opposing Celestial Colonnades. Every version of Land-on-Land hate that's been even close to tournament playable has been very good, so there's no reason to believe this one won't remain popular. I'm honestly wondering if these won't become a true power uncommon, getting close to $5. It's an outside shot, but it's got all the makings.