Well, after going to all the websites mentioned above it looks like evanger's website is the cheapest! The only other one I found that might work out is k9cuisine.com. They offer free shipping on orders over $50 so I would have to buy 5 bags at a time. But, if they like it, it might not be a bad idea.
I contacted the company and they are sending me samples so for now I think I will purchase from them direct.
Thank you for all your advise everyone!
