Gonna have to disagree with my learned colleagues there
Prices keep on coming down with Angels so it's hard to say a definitive price, but I would suggest a stock iR3 with cutlass frame tends to go for, say, 280, where as a Fly iR3 is looking more about 320 ish (assuming good nick, etc)
They're ballpark figures, but I'd bite your offerer's hand off - my girlfriend and I both have Fly iR3's and we both love them. They're good looking gats, maybe tiny bit heavy, but plenty fast and fun.
Don't be swayed the menu's, iR3 capability, etc. At the end of the day, all you want to do is turn it on and shoot fools, not worry about what the temperature is...