Don't know how much you want to invest in this after it is all said and done.
Another factor is whether you will be doing the work or having it done.
Unless the owner is convincing and has documents, you should factor in and perform replacing all fluides and rubber and that includes timing belts.
If I remember right, about $1000 for the stator replacement if it is original.
Not knocking the bike. Sounds sweet and there are many on the road. Just wanted to give you the backside after purchase that there are things to do and cost along with it that might affect what you think is a fair purchase price. If these things have been kept up, then it is obviously worth more.
Unless this bike is pristene and all this has been done for you, TWW's advise sounds about right. 3k is a fair price.