Offer $50 before you see it........gets a no or no answer from most Craigslist,Marketplace sellers. He could part it out for more than $50.
50 miles away.........it will get sold before you get there at $100. Then you have punch the guy in the face. ( see other threads Craigslist and market place first come first served, no saves and no Price negotiation by email)
Sadly, isn't that the flavor of posts on CL and Fb Marketplace sales offers/negotiations, down-payments, deposits, and 'handshake deals' discussed in a variety of recent threads?
I'd offer $33 as a down-payment to 'hold-it until I get paid,' shake-hands on it, and then ignore any calls you get from the guy (you
did call him to set-up the 'handshake-deal,') for the next 12 months, then show-up unannounced to pay the remaining $67, and demand your money-back, because "he's not a man of his word," and it was disposed-of before you could make it back (though you didn't offer him any timeframe, nor agree to any, to pay the balance, and to remove it).
Carnal knowledge of his spouse is expected.