68 Hemi Gtx

I'm still trying to decide how much cash I should show up with to let the old codger know I'm serious.

Show up with as much cash as you think you're going to need (or the max amount you'll pay for it). You don't need to have it all stashed in the same pocket. You can pull a wad out from one pocket and see if he'll take the initial amount. If not, keep pulling from other pockets only if you have to.
Good luck!!!