I'd suggest two things: first, just chicken is not a balanced diet. Try one part poultry, one part cottage cheese, one part brown rice and half part peas. Your dog may simply not have enough oil in the diet.
Another thing is using a little extra virgin olive oil on the ears. It can do wonders. I used to put a drop in my former dog's ears to stop itching.
I understand your need for economy, but vets are also doctors, and they have medical school bills to pay off, staff to pay and all the same expenses human doctors have. When it comes to surgery, I can't imagine a human doctor doing back surgery for $8,000 dollars. That would be a bargain.