I buy Pocher kits, so I'm somewhat familiar with rare kit prices. The most expensive Pochers are somewhere in the $2,000-$3,000 range.
IMO, $7500 is way, way past crazy. For any kit, no matter how rare. How he came up with an asking price like that is beyond me.
But having said that... we all have heard of potato chips shaped like Richard Nixon or images of the Virgin Mary in a cheese sandwich selling for preposterous amounts on ebay, so who knows???
Like P.T. Barnum said, there's a sucker born every minute. And then there's the "more money than brains" crowd that can't be factored out.