I think the only thing that chaps my ass worse is the guy who keeps pestering you like this: like a broken record, he keeps pointing out the bad points on the car, and it's usually something very mundane, e.g. the sideview mirror is cracked, the ashtray spring is broken, etc. Then, he'll keep saying things like, "oh you'll never sell a car like that!" To top it off he'll offer you maybe $1000 less that what you're asking based on those measly "defects." Go fly a kite, dude.
Trust me, I know how this game works. These jerks prey on people that are just desperate to sell their cars. Hell, I'm selling my Honda Accord right now, and I know it's not in
perfect shape, and I adjusted the price accordingly (no pun intended). It has nearly 200k miles on it, but that's not terribly high on these vehicles, and it runs like brand far-king NEW. Anyway, my point is that if anyone tries this lowball crap with me, I'll have to backhand them. FYI, it's worth ~$2350, I'm knocking it down to $2200.
As far as the payment thing for a friend? Eh, I'm in college, so it'd be difficult to say yes to. Unless it's a friend I've had for a long while, and he's in a bind where he absolutely NEEDS a car, I'd more than likely refuse. Yes, not very Christian of me, but I'm living day to day and cannot assume that kind of "creditor" role.