I think that's a fair price...I hunted for the 85L II for months and they kept slipping through my fingers, I think I ended up paying $1800 for it (but in outstanding condition with box and everything). All of the ones I found were $1800-$1900, and the cheapest I've seen one was $1600 (after I had found one of course). But $1500 is definitely a great deal and you probably won't find one that cheap very often.
I would say $1350 for the 85L I is a pretty fair deal, I don't know if I'd call it "great," but definitely not bad. I'm sure he'll take $1300 if it's listed for $1350, but if you could talk him down more, even better.
I think I've read some reviews that suggested the IQ was better on the V1, they are definitely similar and both beautiful. The 85L II is the sharpest lens I own, even more sharp than the 135L.