Sure, I'd sell my soul several times over to anyone willing to make an offer.
It's not like you can physically keep track of a soul (I don't think a post-it note with "my soul" on it is legally binding), so you can just continue selling it as if you still had it and no one will know the difference.
Souls don't actually exist anyway, so if someone feels like buying mine, why pass up on free money?
Someone once asked me why I call myself Unimportant. Simple, I said. As a nihilist, that's what I see everyone and everything as. In the end, we are all Unimportant.