My question was not so limited. I assume A gave no money to B. Did B pay any money to A for any reason? Sounds like the answer is no, but it would helpful to have clarification. Also, if B "walked away from . . . the whole situation," do you even know who B is?If by that you mean did the person buy the desk
Are you A or B? Sounds like you're A.
If you're A and B walked away and you don't know who she is, then this is all academic. It's also academic because no sane person would waste time or money suing over $90 (even in small claims court).