I do 2 or 3 or 4 deer per year, plus a moose/elk or a couple caribou every other year.
Started out with a hand crank grinder. Tough to crank when its not bolted down, and tough to feed & crank by myself.
Also tried the grinder attachment for the kitchenaid - it works good, but very slow to do an entire deer + pork to mix in for the sausage...
My brother has a 1/2 HP electric grinder, he does 6-8 deer each year & loves the grinder, gander mtn I think.
I bought a 1 HP electric grinder from cabelas bargain cave 3 years ago, refurbished AND on sale, if I recall correctly I only paid 125. I love it! Like the warden says, it's somewhat big & heavy, but not that much heavier than a smaller model that I'd get the smaller one out and not the bigger one.
I spend quite a bit of time butchering - I take out all the sinew, all the gristle, "everything that my wife wouldnt want to see on her plate." So when it's grinding time, I want to get it done quick. The 1 HP is fast. :)
The box my grinder came in has a chart on it:
HP lbs/min weight
--- ------- -----
1/2 4-6 35 lbs
1 9-12 57
1.5 12-18 70
I figured if I want to grind 1 deer -- 50 lbs of deer meat plus 25 of pork, 75 lbs of meat would take ~15 minutes with the 1/2 HP, 7 minutes with the 1 HP. Since there was only a $15-20 difference in price that day in the bargain cave and I didnt care about the extra 20 lbs of weight, I went for the 1 HP.
I should also admit that I use tools hard - seems I always buy the "homeowner" tools, burn them out, then buy the commercial version. So I tried to be smarter and buy the bigger motor this time. If I didnt use tools so hard though, I'd probably be quite happy with 1/2 HP.