This is what I'm worried about. I have to put a lot of trust into the farmer and the Processor who cuts the meat up. Who is to say the farmer swaps the cow that I'm suppose to get with a old dairy cow. Or the guy butchering the beef steals parts of the beef that are premium and substitutes with hamburger.
Then figure in the cost of the freezer, the risk power outages or appliance failure and sq ft sacrificed for storage. This sounds like a risky endeavour.
If you're thinking about it in economic terms, your total 'risk' is the amount that you pay for a quarter/half cow (approx $500-600 for a quarter). This risk decreases as you consume meat in your freezer. Your potential reward is what you'd save - in my experience 30-50% off what you'd pay at CostCo, or a savings of ~~$150-250. You can tack on the extra energy of a chest freezer if you want (~300 kw/year, or ~~$30).
AS for risk associated with power-failure, meat inside a well-stocked and closed chest freezer will be fine for at least 48 hours. It varies location to location, but how likely are you to experience a power-outage exceeding 2 days? It certainly happens, but in most places it's rare (especially outside of winter).
As for worrying about the meat being swtiched - if you don't trust the farm selling you the meat, find another one. If you buy quarters and have them processed yourself, take them to a reputable butcher. Most will divide the meat up right in front of you if you care to stand around and watch for 10 minutes (really, it's amazing how fast these guys can turn a 125lb quarter into a few dozen steaks, some rounds, some ribs and a lot of chuck). hunters tend to be a skeptical lot, so they're used to people watching over them.
If the flavor isn't what you hoped for you can make more burgers and stew and chili which doens't suffer in the least. OTOH, I've gotten steaks that were far superior to the ones I could pick up at my local Safeway.
Whether it's worth it to you or not... only oyu can decide. Personally, I got more satisfaction in knowing that I was supporting small, local farms than BigAg - the money saved was just a minor bonus. We met the owners, knew exactly where the farm was and could see the cows develop. we paid for a cow up-front, which got us an even better deal but added a bit of risk should somehting bad have happened (fire, disease).
ultiamtely - your call. It certainly was worth it to us.