Cheapest way to feed multiple cats (good quality)?

I have two ten pound cats and I’m just really at a loss for how to feed them in the most cost effective way, let me know if anyone has any tips or suggestions. I’ve tried getting a box of 36 tiki cat cans as well as an 11lbs bag of dry food from tiki cat as well, that really only lasts like two weeks tho (the bag lasts longer) and costs around $100-$130 per month if im buying multiple of the canned food boxes. I’ve also tried making my own food for them using a premix by EZ Complete, I think it costed around $90 for a 25 day supply but I felt like they were being underfed with that or just not getting enough calories cause the cats would just seem extra dramatic around feeding time, and one of my cats did slim down a bit (he was overweight before so this is good for him.) And yes before this they were eating regular meow mix crap, but one of my cats had a digestion issue and kept getting sick from eating that so I have no other choice but to feed him wet food or just good quality dry food.