Tips for picky eaters?

So my toy poodle (3F) has always been picky and it hasn’t been too difficult to deal with because she would ultimately end up eating her food just to stop the other animals from having it (even if she didn’t particularly like the food). She’s been doing great on the “Purina Pro Plan Small Breed Sensitive Skin and Stomach” kibble, then about two weeks ago she decided to stop touching it because she noticed the cat now gets wet food (so he no longer tries to eat my dog’s food) and my dog will not eat any of her kibble anymore. None of my usual tricks work (mixing water, beef broth, eggs, chicken, steak, baby food, spoon feeding and pretending to eat her food or tossing the cat in front of her bowl-this used to always work)

I took my dog to the vet and we concluded there’s nothing medically wrong and she just wants better food. I was advised to stop all treats and table scraps and she’ll eat when she’s hungry…well six days went by (and lost 1.5lbs when she was already healthy/lean) and she didn’t eat a bite and I noticed her energy crashing bad, took her back to the vet and they suggested trying a new wet food since she would rather starve herself than eat food that’s not to her liking.

So I got a couple cans of purina pro plan and she ate only the small breed versions of the food, the issue is the cost. I can’t stomach spending $40 on 24 5oz cans that will only last 12 days. I’m determined to keep her on PPP, Science Hills, or Royal Canine and we were doing so great with the PPP kibble and I didn’t mind spending $55 on 16lbs. So I’m looking for miracle tips on cutting cost and trying to get back to her old food because between the $600 I’m out in vet costs, rising cost elsewhere, and only making $450-600 a week I really don’t have the means to sustain over $100 a month on dog food for a 9lb dog