In reality it's much easier. I've sold couple of my projects before via different mediums (one is through microacquire - the one OP mentioned, and one was through a connect), and the best way i found to go about it is to be ready to walk away from the deal.

I know this is negotiations 101, but it's tough to put it in practice most of the time if one person wants a little bit more to see the transaction through. Surprisingly, communications skill doesn't play that big of a role, unless you really want to "sell it" most of the conversations goes the same way OP mentioned.