Nick,
I'm with Mike on this one. If you already agreed to a price of $500 and try to offer less when you pick it up, you'd be leaving my place empty handed, even if I didn't know anything about cubs. If it's a complete 800, runs good, good tires, and has all the hard to find 800 parts, it's worth the $500. You're not overpaying. They only made 2300 of 'em. Good thing you didn't try to buy my 800 when I sold it. Nice original shape, hard to find parts, creeper, rear PTO, etc.

It's good karma to honor your offer. Someday, you will be repaid...........