That price is crazy for that age sled.
Pretty much all years of the 800 share the same crankcase/crank issues. The 05 did come with stainless VES guillotines, which solves the problem of the aluminum ones melting.
Most guys that want to keep their 800's around balance their primary clutch yearly and add a wide bearing on the PTO side of the crankshaft.
Even with those options have been done, that's a lot of money for that sled. kbb.com shows retail value of that sled at about 2900.