Best Performance Upgrades for Little Money - Here's My Vote

I wonder if this might be due to the cheap prices though?
if I can build an engine for 500 dollars I might try it myself, but if it will cost 2500 I might have a professional do it
so the cheap entry cost of a chebby attracts a lot of back yard mechanics, while the higher initial cost of a mopar get more professionals wrenching on them?

Engine guys tend to be Mopar. Body guys tend to be GM. Ford is middle ground. Being German, I'll pay more to buy something good and be done, rather than get something cheap and have to buy it over and over. Why does Walmart do so well? I won't say what I think where our society has gone.