Magic: the Gathering - Beta basic lands.

Basic lands are a commodity. If you need some for a deck, you can get them for basically free. Often literally free. If you want to baking out your deck, very rare versions of basic lands (functionally identical in gameplay, just unique art or a rare printing) can cost hundreds of dollars.

Beta basic lands are from the first set of magic. When I played more they were still like $10 a piece- a luxury, but quite affordable for this game. Alpha is the very first printing, but they have historically been a little further out of reach price-wise, and Alpha cards are cut slightly differently on the corners than all subsequent sets, so Beta is a little more desirable for actually playing with. It's considered basically the classiest way to pimp your deck- out of hundreds of printings, this set is by far the most common to find the pros running.