I have been looking for a brass snare drum for quite some time. Had one show up on a local listing, its a 14X6.5" pearl black brass sentitone snare, seems to be in good condition from the pictures, and i can go see it.
I have the exact snare and it's pretty snazzy for a Black Beauty clone. I paid $230 for mine brand new about two years ago, so I think he's a bit high on that price. If I were to sell mine, I'd think $175 was closer to a fair price. Check eBay for those and the others like it (Pork Pie BoB, Pacific Ace, etc...) and you'll get an idea of what you should be paying for something like that.
If you want to see what he current new price is, you could call Interstate music and ask them what their new price is since often the price they quote you over the phone is significantly less that what they post on their website. ... I just called and it's the same over the phone for this one - $277. I still think $250 is high for a used one, though.