The P515 series gaskets are not even steel shim gaskets....they are MLS hence the high price.
I have covered that before but will repeat as many times as folks need: If you want the steel shim spec, do not order the P515-series part numbers.

The old P4286754 are much lower priced, they are now made of stainless instead of mild steel which is a nice upgrade, but availability appears to be poor at the moment from everything I can gather. They appear to be on backorder right now with no ETA listed as of yet.

If someone wants the old spec mild steel like what direct connection sold in the '70s, order OEM gasket number 3614824. There are a few dealers that still have it. It will be the silver painted mild steel most of us are accustomed to.