
Royal Canin is a good quality food. The other brands of the same quality will cost you around the same price.
If you actually work out how much each meal costs, I think you will be surprised on how it compares to the cheaper ones or tinned food. With the quality foods you don't have to feed so much and you don't have to pick up so much from the other end. ;) Are you buying it in a 15k bag? That is the cheapest way to buy it.
If she is fussy, try adding a little Naturediet with it, it mashes up well and sticks to the food. I have put Royal Canin in the microwave for a few seconds to bring the oils and smell out of it too, it seems to make it a bit more tasty.
You can find out about Naturediet at
http://www.nature-diet.co.uk/Sandra