Dog food question i need highest quality food suggestions?

I have an american bulldog (roxy 11 months) and a pitbull (dax 6 months) and they're on nutro ultra large breed puppy holistic. They seem to be doing well on it roxy has food allergies and I've tired almost all the non holistic foods such as science diet purina eukanuba iams royal canin and so on. So I'm on a budget and what I'm feeding is as much as I can afford its $50 for 30lbs and I use exactly 2 in a month I can't afford to spend more than $100 a month on dog food but id like to find out about some of the highest quality foods I don't imagine I can pay less $ for the food but id just like to know my optionson if I can get an even higher quality for what I pay now. On here I've heard that what I feed is "low quality" but it works well for them roxys food allergies are bad she breaks out in lumps gets soars in her paws inside her mouth on her stomoch she gets the runs and vomiits she gets fungus on her skin and 'mults' goes bald! that's what I get for feeding her bad food so please don't reccomend anything low quality with loads of corn and preservatives such as science diet and purina. Also they need large breed puppy formula