Imagine this, there's a neat little space pirates game. You buy an NFT ship, you buy some space missles, some fuel, contract a crew, and you go out. Maybe the dollar cost of all this was $60. Cool. You go out, you blow up the first ship you found. You spent 3 missles at a cost of $10 each, but you got a whole ships worth of minerals worth $60, and some more missles. There's some capital gains! Now you keep going, and you blow up another ship (hey doing good buddy!) how do you calculate the cost basis for the missles you used? Your looted missles are mixed in with your purchased missles. You keep going, your ship is blown up, and now you need to write it off, fortunately you were able to recover some of your stuff because after your last battle you put some in storage.
You had a great time, but now it's January and you have literally all the same tax problems as a legimite space pirate business.