Everyone saying 2500$ makes me smile (in Canadian mine is like 4K then)!
In all honesty, I think $2500 for your machine is totally fair. I have no favourites between DE, Bally, Williams, Stern - I am not a fanboy in the least.
JP sometimes can play a little klunky (?), but IMO it is a very underrated game. I think the rules are great for beginners and novices (perhaps easy for the pro - which I am not). The ball-eating Dino is one of the greatest toys in pinball. The new code being worked on is only going to improve the quality of gameplay. The music is stellar - especially through an external sub, and the theme is timeless for children and adults alike.
So far, I have found that it is one of the most fun games out there to Mod!! Soooo much you can do with this machine. There are some sellers with great ideas on the market and others that are working on some BIG cosmetic changes!
It was my first pin too....there are better games out there, but for sentimental reasons, JP will never leave my stable!
Good luck with your sale.