It is definitely regional and I see them appear in waves. I've picked a up good runners and the truck with them for $500 and I've seen runners go for more than that by themselves. I've even seen seemingly frozen engines try and go for over $100. Flat 6's are definitely harder to find. I think mostly they get scrapped and no one thinks to try and sell them. I got both my 8 and 6 with the trucks for $500ea. The 8 is a driver and the 6 needs TLC to get it running.