C.A.
I don't know about finding this stuff cheap-the price is outrageous.
We tried it due to reflux and it made the problem WORSE. And I bought two big cans of the stuff, one for the house and one for the sitter's from our Walmart Food store. That cost me just a shade over $50.
I would recommend Walmart for the initial purchase and KEEP THE RECEIPTS. If it doesn't work out they will let you return the formula even if you opened the cans.