Prices seem to be all over the place. I look for the 2012 and later engines. Use this as a guide. As of April 2023 you can buy a new crate 5.7 for about $6000 and a new crate 6.4 for about $8600 from Bouchillion Performance. Probably find it cheaper or more expensive depending on where you shop. This motor only no trans no accessories. Now if you look at www.car-part.com its a salvage site. Plug in what your looking for and that same 5.7 or 6.4 motor and trans with some accessories is about $8000-$10,000. Plus a core! The 5.7's are cheaper than the 6.4's. I think they are way too high on that site. Especially comparing to the cost of a new crate. Perhaps there is room for negotiating. Seems like the engine/trans combos on FB marketplace go for $5000-$6000. But that could be a shady deal depending on the seller. You don't know if these used engines were stolen, in a flood, or have a rod knock, etc. Its a gamble even if you turn the engine over by hand. While I'm not looking for a warranty on a used engine, honesty of the seller is critical here.