One of the most important things about Magic: the Gathering is having lands to play your spells. This is why full art basics from Zendikar, Unglued, Unhinged, and now Battle for Zendikar are such good investments. It's why foils are even more so. It's why fetchlands fetch such a premium. Shock lands retain good value because they're the best nonbasic mana-producing lands in Modern. But remember that some decks are mono-color and therefore need a crap-ton of basic lands.
Enter Swamp #238 from Shards of Alara.
How about the foil?
If you think this is interesting, check out this Swamp from New Phyrexia:
There are a handful more over $2, and this is just looking at Swamps! I'll say one thing: I can never look at basic lands the same again! Some players really, really like particular arts on their basic lands. While I don't necessarily suggest raiding your local game store for the non-foil basics over $1, it's just a good idea to watch what basic lands are actually worth some money. Most buylists don't consider them, but you can always EBay them, Heck, you can even try to trade them off on PucaTrade!
So remember, if a particular land art looks super sweet in foil, look up the pric.e. It may be worth more than you'd ever expect.