Offer him $200. You can get that bike new with those components. Some of the stuff on craigslist are high priced. Last week a saw af Flite saddle for $150. Well, I can buy one for les than that anytime.
Mind you they do have some great deals. Last year I picked up a set of 4 snow tires on rims brand new for $225 cash that would have cost me $1400 plus taxes. Recently, I got a Sony Wega 2005 32 inch TV for my son's game room for $75. I have one of those that I paid $1500 for some years ago.
As far as bikes go I have had not much luck there. My last bike I bought on Ebay and bought some components there as well, very cheap.