When it comes to coffee grinders, "you get what you pay for" is generally true, but there are a few caveats that go with that, depending on how you use your coffee grinder. In general, the heavier the coffee grinder, the better. That's because large & heavy motors in coffee grinders produce lots of torque at a relatively slow speed. Coffee grinders with large motors have enough power to grind the coffee beans without heating them up. Of course, heat will damage the flavor of the coffee.
If you are just grinding coffee for yourself, or just for yourself and a partner, a smaller coffee grinder in the $100-$200 range will be adequate. But if you intend to grind lots of coffee, you will burn out the small coffee grinders much sooner than you will the large coffee grinders. The very inexpensive coffee grinders are meant more for occasional (not daily) coffee grinding, or for the regular grinding of spices and other condiments.
So heavy weight in a coffee grinder is good, but a small coffee grinder can be adequate, depending on how much coffee you intend to grind. The final caveat is about the "dosing" function in coffee grinders. While the dosing function seems to be an "added feature" in a coffee grinder, and hence, "better," this might actually be a bad feature in your coffee grinder depending on your lifestyle. See the text following the icons below for a word about the dosing feature in coffee grinders.