Totally absurd, but fun to play with.
I do find sometimes it says it'll be cheaper to buy it, but in several cases I'm positive it's not, or the price of the product in store vs from the recipe isn't directly comparable.
The example of refried beans is complicated. If you buy a can of refried beans, it won't be as high quality as the recipe provided. The recipe is rich in butter and onions. A can will likely have lard or vegetable oil in it, and very little onion (likely powdered). It also claims it's cheaper to buy the can, but it's because initially the recipe suggests buying cans of beans. If you use dried beans, you're probably spending about the same amount but getting far nicer refried beans.
Anyway, it's a fun project, and the things I noticed aren't really problems and are easy enough to negotiate in the interface. I had fun with it.
Also, pretty sure we don't typically get milk from pigs.