This is an interesting, and IMO uncommon, response. Thanks for the honesty! :)
You're right social constraints are going to modify each condition; many people sleep with others in sympathy, for example.
If I imagined she was better-off, $500 would be plenty for ninety minutes of work (including drive time, chit-chat, etc.)
That's an interesting figure; because it is roughly how much a prostitute would be paid (I use that example only because it is the most readily available price for sex we have). So, possibly, there is an inherent social value for non-free sex we subscribe too.
My "ideal" price is zero; I sleep with people for free all the time
This syncs almost exactly with the response most men gave in our survey
