DEFINTELY PAY THE $400 EXTRA! This MacBook Pro that you are thinking of trading is WAY BETTER than the Dell you have. He probably just realized how dumb he was because he could sell it for a lot. So I say it's worth the $400 extra. Come on, it's a MAC!
If it were the latest versions of the MBP I would probably go for it, but this is the version that was just replaced. If I went out to get AppleCare, I'd have to tack on close to another $350.
I was hoping to sell my M1330 for $1,500, but nothing is going my way, people offer $800 which is a joke...
I keep going back and forth, I know I'm driving you guys and definitely my wife insane!