Unless you can get the original owner to show you a sales receipt you can only guess what they paid for it originally. It's all a matter of supply and demand at the time. Some locations where sales were brisk tacked on "market adjustment prices" other dealerships felt since it was the last year of the AV and sold as a special edition they tacked on further price increases. Most dealers sold at suggested msrp though which was somewhere around $50,000 depending on trim levels etc.
The seller is probably attached to the AV and feels that it is rare and worth more then it really is but again supply and demand will show them if someone also agrees and pays the price.
Thanks for the replies, I am fully aware they can ask whatever they want. I have an 03, I would hate to see it go, but living in the northeast winters and salt are taking a toll on the body behind the cladding. I’m hoping to repair it !! I would happily buy a 2nd one but paying 15 k over book value seems a little crazy. We have a 79 z28, a 98 suburban, I try and take care of our vehicles. Losing the 03 av would be difficult, the fact that they quit making them is the worst part.