User blog comment:Willbachbakal/My BioShock Sequel Idea Dump/@comment-1330314-20100530205952

Ooooh, right. Whoops.

Okay, now that I know whatwe're talking about, I don't think ADAM should be bought, since a) it would stop being a unique, hard-to-find resource and b) it could be farmed by killing Splicers or gambling.

As for exchanging items, I don't really see the point. Everything can be found in the game and besides, why would vending machines want to buy stuff instead of selling it?