Due to the new Gen releasing and many people wanting to do the same thing you are doing the prices on the 5770's have dropped so you might want to rethink the pricing -- can get a 5770 brand new with warranty for $99.99 After MIR from Newegg
so $115 used is a bit high !!
What brand are the ones you are selling ? Is the warranty on them transferable to the purchaser and how long is it ? Has the warranty been registered ? Have the cards been OC'd ? would you be willing to sell them one at a time? ( for those like me that already have one but might want a second but have no use for the third )