You have a number of different options:-
a) PM Lex Rooker
http://www.rawpaleodietforum.com/profile/?u=28He has found some ingenious methods to reduce the costs of raw, grassfed meats by ordering grassfed-meat which was "pet-food" grade, but still fine to eat by humans, according to Lex. This website might also prove useful:-
http://pets.groups.yahoo.com/group/CarnivoreFeed-Supplier/b) Buy raw wild game. This is usually much cheaper than raw, grassfed meats but is, ironically, much, much higher in quality than the latter. Gte it preferably from farmers, hunters or farmers' markets as shops selling wild game will add further retail-costs onto the price.
c) Eat raw, grainfed meats. Generally a bad idea, but still "less worse" than eating cooked, grainfed meats. Organic means f*ck all, it would be far better to get hold of raw, nonorganic, grassfed meats instead.
d) Prefrozen grassfed meats are a LOT better than nonfrozen grainfed meats.
e) Practice Intermittent Fasting(IF). This involves eating one large meal every 24 hours, eaten within a 4 hour window of time. The meal should consist mostly of meat - the result will be that you will eat a bit less, overall. Also, the more raw animal fat you eat, the longer you will remain without hunger, whereas eating lots of carbs increases one's appetite, and therefore increases one's food-costs. Also don't drink water with your foods, as drinking such will encourage you to eat more than necessary.
*Be careful not to go raw, zero-carb until you're sure you can handle it. As for raw liver, there's no danger re toxicity. I once overindulged in raw liver, and my body just adapted and squirted it out the other end without absorbing it - thus, I learnt that raw liver was fine if I consumed no more than c. 0.5 kg a week/2 weeks. Others, though, can handle much higher amounts, it all depends on the individual.
f) Get hold of other raw organ-meats, such as raw tongue, raw suet, raw kidneys etc. Organ-meats are dirt-cheap by comparison to muscle-meats, as there is little demand for them.