Price varies depending on what engine you get and what year it is for the Chryslers. For example, the 392 is the most expensive with complete engines being a couple grand and bare unmolested blocks going upwards of $1k. Next would be the 354 which is usually half or less than a 392, and then the 331's with the later 54+ 331's being more valuable than the early 331 extended bell motors. Rebuilt kits are in the $1500+ range with crank, rings, pistons, cam and gaskets. This doesnt include the additional cost of a front chain cover to allow for a BBC water pump to be used.

Really depends on what was found and what condition it is in, I am not positive but I believe one of the guys from RM mobarn was trying to sell a 331 longbell engine for $500 and it took awhile.