@thor Try wild emmer if you can find it. It should be cheap, but it's very nutritious. It's also richest in proteins compared to other… let's call them cereals. Potatoes are just sugars — you do get your calories, but I have a problem feeling "full" eating only potatoes, you just get feel hungry again in an hour. Emmer might be a little hard to digest to some, but if it suits you, you're in luck — it's hands down the best side dish I could find.
@thor Oh, yes, it also takes a bit longer to cook, about 40 minutes. My rule of thumb is to wash it and put it in cold water with spices for a few hours before cooking, this way it takes shorter to cook, it gets softer and just tastes better.