> Marx would have a word about use value vs exchange value.

Sounds like a semantics trick. Value is value. Sure, something can have a different value if you exchange it versus if you use it. It can also have a different value if you eat it, or drink it, or smash it, or wear it, or gift it to a family member, or gift it to a friend, or gift it to a lover. "Exchange" is simply one way of use.