Like you mopac I had several thousand die cast vehicles as I used to be a Hot Wheels and Matchbox collector/ seller. The most I ever had was 5,000. Took up three walls in my basement plus I forget how many of those plastic containers that have pullout drawers. I never got $750 for any one of them but I did sell several in the $200-300 range. That was then turned into train buying money or I bought somebody's die cast collection to resell for train money. Still got just over 2,000 of the things. Some of those cars and trucks look fine on my Flyer layout. Matchbox made some nice stuff way back when. Since my layout is in the early years of the steam to diesel era, those cars and trucks go a long way toward identifying and dating the years, especially those old Matchbox Cadillacs and trucks.