I used to have a great local source for pig fat, a local custom butcher who has since retired. Too bad, because his prices were amazing, especially considering that he included all the leaf fat, too!
Fortunately, for the second time in 3 years, we've split a half side of beef with friends who raise cattle for custom butchering. The butcher saves all the fat for me to render, and will give me as much as I want from other orders where they have him throw away the fat. It's so much that I have to freeze a lot of the fat, and render in batches throughout the year. So, in order to use what is available and affordable, I'm reformulating my beloved high-lard soap recipe to a high-tallow soap recipe.
Anyway, if you can find a local custom butcher, that seems to be the key to reasonably-priced fat to render. I do highly recommend an
electric turkey roaster pan. They are very inexpensive, especially if you can find one at a thrift store. They hold 2x - 3x as much as the largest crockpot. The flatter surface area makes for faster rendering, too. I plug it in out on the patio so the smell doesn't permeate my entire house.