Nice price, but I'd vehemently protest! Find something wrong with the bike like scratches, gouges, ugly chain, anything...use your bargaining skills.
I'd offer $300 as my final offer, but I'd take $350, just in case!
PS.
In America, we bargain...That's what capitalism and the free marketplace is all about. Beside, you can't always be too sure about the bicycle's condition. If you must lose anything lose less...