Depends...I've had a few different grinders from around 50$ and up and I had incidents of metal shavings in each. I upgraded to a Spacecase titanium (around 80-90) and love it.
At my local shop the 4 stage SharpStones and Chromium Crushers were $30. The smaller ones were $20, the small ones with a see thru top were $30. Dont get a plastic or wood one either.
for sharpstones run paper through it before you bust your weed up.... that will get rid of any aluminum shavings or dust left in it from the cutting
how come some of the grinders have multiple compartments? does that make it better or something? does that mean i just put in a piece of paper and grind it up in the grinder?
they should have 3 levels.... level 1 grinds weed into level 2 weed stays in level 2 (middle) kief collects in level 3 (bottom)
Sometimes grinders have keif catchers in them. If you get a decent grinder with one, you will collect alot of keif. In my opinon their worth it, get a Sharpstone. I have one and love it.
I really really really recommend chromium crusher grinders. I have a space age, chromium, and sharpstone. and the chromium has alot of good sharp strong teeths so i would get one of those