Advice on buying junkyard engines?

I recently went to some local yards for the first time in a number of years. Some things have changed quite a bit. And I can imagine it is likely somewhat different up north here compared to the south, but this is what I found. Because of the increased population and the scarcity of land up here, the remaining local yards work on a short turn-around and the common practice is to immediately scrap anything pre-2004 when they pick it up.

I was looking for some core Torqueflites, and after most yard workers stopped snickering they told me there was no profit in keeping that old of stuff that is seldom requested when they could immediately sell Honda and Toyota engines and trans. The couple of really old yards, the worst mess of the bunch, that did have a few trans cores stuffed in shipping containers, wanted so much, starting at $600 for a core, I easily passed.

If you want a trouble free reliable motor and don't want to build one, why not be done with it and just buy something like a Summit has for $2090, or something better like Blueprint offers on this site?