It's a tenor, not an alto, but that's a good thing for you, as tenors sell for more than altos. Even so, I think you'd be hard pressed to get $6k+ for it. For the value on a Mark VI, it all comes down to 2 things : condition and serial number. Your horn looks to be in excellent physical condition, but the serial number is too high to get a premium price. If pads are new-ish, I think you could sell it relatively quickly in the $5000 range, maybe $5500 if you are prepared to hold out for a top price, but honestly I don't see it going for $6000 unless it is just about mint condition and you've already put a premium pad job in it. And even then, it wouldn't sell quickly.

I agree completely with Jonhuff.

In a pandemic, 6500 is quite a retail price for a late model Mark VI. Nobody is out playing music in public right now.

I do live in Springdale, Close to you. I see you have it listed on Craigslist here locally.If you still have it in a few weeks, I may contact you. I refurbish and collect vintage saxophones, and vintage mouthpieces. It is a hobby of mine away from a Banking Career. I have eye surgery tomorrow, so I wont be playing for at least 10 days.

Its a nice looking horn.

Good Luck

huge help knowing it's a tenor, JonHuff. much appreciated. 

sounds good, historicsaxwhisperer. my youngest brother and i are in cincinnati for a bit because we live in nyc and chicago respectively, which are covid hotbeds. there's a chance one of us will take the sax back with us to sell, as i imagine either of those locations are better markets. but if it's still up on cinci craigslist, it's available. hope your surgery goes well tomorrow.