Here's a Mark VII for much cheaper, even if it does have some crazy engraving.
Here's another one for less than 3 grand with no engraving... probably still a good horn.
Dealers intentionally price their wares significantly above market value if their clientele consists, generally, of band kids and parents. That is to say, people who, unlike many pros, don't know the going street price for vintage and modern equipment. What I'm saying is, the horn is probably as good as any given Selmer (which can be a gamble, but if you find a good Selmer, you find one of the best horns ever made, regardless of vintage), but the shop owner is definitely selling it for too much. Mark VIIs should generally go for around $2000-2500. Not that they're that much worse than Mark VIs; as I said, I'm sure there are VIIs that outplay VIs, just like there are Series IIs and IIIs that outplay them all. It's just the going market value.
It pays to do your homework!! Check ebay, check junkdude.com, robertoswinds.com, check saxquest.com, find out how much this stuff is going for before you let a dealer rip you off.