What's are good treats for cats that are nutritious, affordable and easy to get?

Normally I just buy the basic stuff at PetSmart. But I decided to treat my cat and got some expensive stuff from PetCo and from a mom and pop shop. So I really have two questions. What's the best of the three I got in case I want to really treat my cat every once in a while and generally speaking, what's the best affordable and easy to get cat treats that I can find around that won't bankrupt me? I am trying to avoid corn and all the other fillers and meat buy products but when I get the cheap stuff, I have no choice but I can't afford the expensive stuff all the time. The three expensive ones I got are Innova Cat Treats which cost $3.99 though I don't think that for its size it had the most treats inside. The next one is chicken flavor Liv-A-Littles Healthsome Cat Treats by Halo Purely For Pets. This cost $4.99 and seemed to have a bit more in it than others for its 3 ounces. The last of the three is Wellness Pure Delights Turkey and Salmon Jerkey. This cost $3.99 and says it has over 300 pieces in it. I'd say this would be my expensive choice, but I think that while she eats it, she reacts with more enthusiasm with things the can bite that are hard. I think think it's that cracking sound she likes when she bites into something hard. I tried some sardine jerkey from Wal-Mart for $2.99 but while she tried to eat it, she has a real problem cracking the harder dried jerkey. I get the feeling any treats have to be able to fit in her mouth for her to want it. The one over the counter I have been getting regularly is Whisker Lickin's cat treats by Purina. I get the hard ones, not the soft ones. They're not the best, but at $1 a pack, the ingredients look better than other over the counter. I've tried the Friskies, but then learned the ingredients stink. So I need to know what's the best of what I got if I can only get one of the expensive ones and if there is a good one better that I should look for that is fairly easy to get, feel free to let me know. And what's the best of the cheaper ones so I can have plenty of treats on hand. Thanks in advance for the help!