There have been many reports of improved health when chronically ill pets were switched from a commercial product to a raw dog food.
The cost versus kibble is dependent on whether you make your own or buy the more convenient prepared food. If you make your own the cost is similar to the higher end kibble brands.
Of course there are other considerations such as the fact that raw food should create less digetive problems for your pet and therefore less visits to the vet.
You can look up more information at this web site.
http://www.theglobeandmail.com/life/relationships/raw-meat-for-dogs-is-the-theory-half-baked/article4401112/
