I know you're quite a bit younger than me, but even when I was your age I never, ever bought things for myself....Tango's needs always came before my needs and still do. I buy absolutely everything for her, I even pay for her vet bills as she is solely my responsibility. Of course, I probably have more money than you, but that's not the point. Instead of 'rewarding' yourself with new bettas (when you already have some), your dogs' needs should come first. You do not know that she won't eat a better quality food until you try it. Pet sotres DO take food back, even once its openened as long as you haven't used much of it. It never, ever hurts to try things. I understand that you don't have a lot of money and your mom doesn't either, but your dogs needs are important. There isn't really any reason that Lily needs to have a small breed food, nor is there any reason that Roxy needs to have a large breed food. Yes, in some ways they're beneficial, but a food for the both of them is obviously easier and cheaper. Tia eats regular sized kibble without a problem, Lily should be able to aswell. In a good quality food, the kibble really isn't all that big. And, as others have said, Roxy could jsut as easily it the small bites. I don't really know what else to say without repeating what everyone else has said already. Good luck, and I hope you'll understand that your dogs' needs should come before your wants (you don't need anymore bettas, and technicaaly, you're not saving them because other people will buy them).