It depends on what you want to do with it (bar hopping, long-distance cruising, short distance, etc.)
It also depends on what your friend has to have for it.
If I were looking for a bar hopper, the fatboy wouldn't be my first choice, but it wouldn't be a bad one. With throw-over bags, it'll work for some weekend mid-distance touring, but not the best choice. I'd also try to stick with the M8 versions of the Softails, as they are far better.
Harley's get a bad rap, especially from fans of Japanese bikes, but the truth is, modern Harley's are pretty dang reliable. I've known several who've ridden 100,000+ with nothing more than regular maintenance. Harley's become unreliable when people try to mod them with crap aftermarket parts and try to make them something they're not - race bikes. The aftermarket support for Harley (and production support for that matter) is unmatched anywhere, by anyone.
I'll probably get flamed for that, but I've owned cruisers of nearly every brand made in my many years riding, including a Victory. I loved each one of them, and they all had their ups and downs. But for ME, Harley makes the best cruiser on the market, hands down.
ETA: For the record, '06 should be pretty cheap - last year for 5-speed, last year for 88-inch twin-cam, still has the crap tensioners (unless your buddy upgraded them). Use that for negotiation. I realize this is an old thread, and you've probably either bought it or passed, but just in case...