Yeah food sucks its soo expensive and you can go through alot..
I make my homemade food use some shrimp, some pea's, lettuce, garlic and whatever other vege's I can find, all the vege's are cooked.
While the vege's are cooking I blend up the frozen shrimp then drain the vege's and add them too, then blend it all up. The trick to keeping it together is adding gelatine to make it set and also not blending it to a pulp unless your feeding it to baby fish..
Once your done you can stick it to fish bags flatten it out and stick it in the freezer and just break off chunks stick them straight in your tank.