I think Blueridge Beef is one of the cheapest pre-made raw diets, it also doesn't have veggies so you're not paying $2-3/lb for veggies. If you go to their website they have a listing of who sells their products. I used to buy a 30lb case for $60-68 depending on what meats I got (duck and venison are more and rabbit is really pricey). But, people in other states get it for even cheaper.
A little pricier, but better quality is: Pet Food Online
They use grass-fed meats. I purchased meat (not their pet food mix) from them for my dog and I was very pleased with the packaging (free delivery too) and he seems to like the taste.
Pretty much no pre-made raw is going to be 'cheap'....but I feed my senior JJ Fuds pre made and its about as reasonable as you can get. I have also noticed that Steve's Raw, and Northwest Naturals has been reasonable.