First Pin -- Midway Race Way with export (plastic) backglass. Bought in June 1978 -- $50 Still have it too!
Pins in the 80's -- Woodrails were $50, Wedgeheads $25, solid state games (since they were still new-ish) $300-$500
Pins in the 90's -- Bought HUO TZ for $700, and 25+ more TZ's from ops for $500 or less, they wanted 'em gone because they were a service nightmare. CV -- $400. Indy -- $350. Early Solid State games, $50-$150. Bought literally hundreds of Seeburg jukes for $50-$150 each which easily sold back then for $500 each.
Best find -- Get a call from an op in the early 90's. He wanted to liquidate all of their EBD's. Nine in total, take all or take none. Bought all 9 for $125 each and the op included numerous boards, NOS displays, two NOS playfields, three NOS plastic sets, and a NOS backglass. THOSE were the days!! LOL