I also believe in most cases you get what you pay for, but that said, I have used an Origin 8 Corsa knockoff on one of my seldom used bikes and it is great for short rides --- the foam is too soft for anything over 15 or 20 miles, -- but it has the look - especially for a bike you don't want to put a lot of money in -
I am almost exclusively a Turbo (or turbo style) or Corsa user -- the new re-pop Turbo saddles are not very bad in price if you look around, (still around 50 bucks though) -- but I keep an eye peeled on ebay on occasion for decent used examples , as well as stuff like Vetta's and Avocets that have the same profile ---
but buying a premium older seat used for 20 bucks is not what this "cheap seats" thread is all about