Use prepared gluten-free products judiciously.
For me, there are two categories that require the purchase of specialty gluten-free products:
Replacement. Even with gluten-free noodles, spaghetti is still an inexpensive and healthy meal. We always keep on hand a supply of gluten-free pastas and noodles. We've had good luck with corn noodles, though I hear good things about the Quinoa pastas. We also always have gluten-free bread and flours so that we can have things like sandwiches and cakes. Cake is especially important, as we couldn't attend birthday parties without bringing our own.
Convenience. Whenever we travel, and even when we eat out, we bring our own gluten-free convenience foods. This isn't how we normally eat, but we always keep a good supply of snacks on hand whenever we go anywhere, so that we aren't in a situation where our kids can't eat.
When you buy gluten-free products, you've got some choices. There are tons of wonderful online resources, however, I feel it's important to support my local natural foods store, and, if your "normal" grocery store makes an effort to carry gluten-free products, encourage it by buying them! Buying locally may not be the cheapest option, but to me it's investing in having these products readily available.