I just got a brand new 7790 for 122 Euro, giving me 260 MHash/s and only pulling 50 Watt.
if you do rebates and live in the USA and not in one of the states where you have to pay a sales tax to newegg (like texas, hoho), they have the MSI 7790 at $100 again
http://www.newegg.com/Product/Product.aspx?Item=N82E16814127726the games arent worth as much now, but bioshock + tombraider, i couldnt imagine getting less than $15 after fees on ebay for still. so like $85 (€65)
i get 310mhash on my 7790's, but that's with settings that wouldnt be the most efficient for most people, i just get really cheap electricity
i bought a 7770 when i saw one for $80 w/ refund + games (ended up being like $65 or so), it does like 210mhash
those were bought with mining for a month or two then reselling in mind. if i bought one now, i'd probably just do the rebates + sell the games + then sell it new in box on ebay