I just switched my dogs to Wysong Anergen dry food along with raw chicken and supplemental feedings of fish. The Wysong is sold in 4 and 8lb. bags. You can buy 4 8lb. bags, totalling 32 lbs. from Wysong for $42.00, but the shipping is $21.00 (for me anyway). Still that may be cheaper than what you are paying now. You could check retailers, pet stores, etc. in your area to see if anyone carries the Wysong products. I was fortunate enough to have the feed store in my area order me 10 cases, so I could get a better price on it. This particular food can also be fed to cats which works out great for me since I have cats who also need an allergen diet.

This food is not classified as a "prescription diet" but only has a limited ingredient diet. It has lamb and brown rice, flax seed, oatmeal and some other good things. It's free from preservatives, corn, wheat, beef, by products, etc. So I don't know if it would work for your dog, you would have to be the judge of that. Like you, I couldn't afford the price of the prescription food. I was feeding the cats the Royal Canine and at Petsmart that was $36 for an 8 lb. bag. To me, that's totally insane and a rip off.

You can get foods that won't bother your dog's allergies...

The key is knowing which foods your dog is allergic to...

what are the ingredients in the food that you are buying from the Vet... probably duck and potato, or venison and potato, or something like that...

What were the ingredients in the food that you were feeding the dog when he had skin problems... probably chicken and corn.

The ingredients are listed on the bag.

A typical food that is commonly used for an alternative to chicken and corn is lamb and rice.

There are a few threads on this forum and lots of information on the web about an elimination diet. Your vet can help you with that also.

There's really no such thing as a "hypoallergenic" dog food. It just depends on what particular ingredients your particular dog has developed a sensitivity to.

Lamb and rice used to be what vets prescribed for food allergies, because so few dogs had been exposed to lamb that it provided a good novel protein source. Nowadays, virtually every dog has been exposed to lamb, so it no longer serves that purpose. In addition, a long-term diet of lamb can lead to excessive copper consumption which can lead to toxicity and liver damage.

There are plenty of other options now that might provide your dog with ingredients that will be tolerated well. These days, it seems more dogs than ever have problems with grains, so finding a grain-free kibble or one with exclusively rice (generally the best tolerated grain) should help.

I feed my dog Natural Balance Duck and Potato because it's good for dogs with allergies. They also have a chicken and sweet potato formula that is grain-free. I buy it at Petco and Petsmart. If you buy it at Petco after every 10 bags the next bag is free. And as a club member every once in awhile they'll send you a $5 off coupon or let you know when it's on sale. I think I pay around $45 for a large bag. Petsmart even sells the dog food that I thought was only sold at the vets but if you bring your dog to their vet and they approve or go through the right channels you can get a special card that permits you to buy this food from the store. That's the route I would take if I had to buy vet-only food because Petsmart has better hours, and is more convenient than driving farther to the vet's office.

Here is a link that might be useful: Natural Balance

We've also used the Dick Van Patten Natural Balance grain-free Limited Ingredient Diet (L.I.D.) foods. We've used mostly the kibble, although we've added their canned a couple times too. It's a high-quality product. I'd definitely recommend the grain-free versions since dogs can have difficulty with grain. Based on our own experience, we echo flyingflower's post and recommend it too. We use Petco for their every-10th-bag free promotion.

Here is a link that might be useful: Natural Balance grain-free allergy formulas

Natural Balance is great. I recomend at least supplementing your dogs diet with ANY of their products. I also know that this can add up quickly. You might look into a BARF diet. Going to a local butcher, get some organic meats dont cook em, just give them to your dog. read up on the barf diet...good luck
By the way, the higher product you feed your dog, the less they eat and the less the defecate.
Plus they stay healthier.