Not sure where you can get ' em in your neck of the woods, but just a few thoughts.
You can go manual or electric.
In general, the manual models are built much stronger. I'll tell you though, when grinding stuff with gristle or bits of bone, it makes for a workout.
I first bought an electric jobby for about $100, kinda like this
During its first use, a bit of bone got in there and the force of the blade against the plate actually broke the locking ring which holds the plate and blade in place.
I had it replaced, only to have the gears break down a short while later.
The wife bought me a similar model for Xmas. Lo and behold boxing day sausage making and the plastic gears on the drive shaft grind away...returned that baby day after.
I vowed my next electric machine would be in the $500 commercial range.
I don't necessarily try to grind gristle and bone (actually I try to remove as much as I can) but I think if you go for the inexpensive electric model and try to grind bone, it might be the last time you'll be using that grinder.
Like I say, the manual one is still grinding after about 12 years. Looks like this