That sounds like a good horn to me. If it is in good condition and it plays well, 3500 for a Mark VI tenor is about average. Play it before you buy it if that is at all possible and see how you like it. Its basically a personal opinion question, and your opinion counts more than ours because after all, it is your money that it will be bought with. Try it, see what you think, and good luck.

I have a MarkVI 159xxx. It has a beautiful mid-bright resonance and I wouldn't sell it it for $35,000. I would agree on testing it first, but if you're like me you are going to love that horn!