Wow

I would think that is a bit high but then again a good paint job done right is alot of work. Is the car already stripped down or is he removing all of the interior, exterior, all prep work etc. It should be a lot less if al he has to do is get all the old paint off and spray. If you add in all the other work plus cutting out the bad metal and welding in new stuff that makes for alot of work. You should get a couple of quotes from other places and see what they say (don't mention your friends price). As far as being a good friend, be careful, 8 grand can spoil a friendship real quick, even if he does a good job, your doubts now could have you regretting and feeling taken advantage of later. Something to think about.