Read the labels, carefully, on everything. Usually now everything is labelled with allergens, including gluten, however you need to be the boss of this or you’ll find yourself sick very quickly. Also, companies can change ingredients without warning, so check up on your favourites from time to time.
Understand what is and isn’t gluten-free before you start. Do your homework. Ignorance won’t save you! This means understanding grains, ingredients that you wouldn’t normally think would be made with wheat or gluten-containing grains, and understanding food science: they use gluten all the time for the weirdest things.
To save money, avoid the overpriced, small gluten-free sections at large supermarkets – instead, find an online retailer or a cheaper version of the same thing elsewhere where gluten-free items are considered the norm – if your local supermarket has a great gluten-free section at good prices, knock yourself out, but keep in mind there may be more cost-effective options. Supermarkets are famous for cashing in on ‘health fads’, of which gluten-free is often considered.
Eat fresh, and avoid packaged foods altogether. Meat, seafood, dairy, fresh fruit and vegetables, and specific gluten-free grains are all gluten-free, so go nuts. There is no reason to starve. You really have no need to ‘replace’ everything with the gluten-free version, which is often full of crap anyway. Potato starch is not a food group.
Wheat-free is not necessarily gluten-free. Rye and barley also contain gluten, so check your ingredients.
Ask. If you aren’t sure about a product, you really can call the manufacturer and ask them.