What to feed?

really struggling to make a decision and need some guidance. I have a four month old Bernese mountain dog and an eight month old golden retriever. I currently feed them Hills, sensitive skin and stomach salmon puppy food. Each bag is $67 after tax and they are going through over a bag a week. Hills only makes the medium bag in this mix so I don’t even have the option to save and get a larger bag. I’m looking for a more cost-effective but still good choice for my dogs. Any recommendations?