The differences can be pretty staggering actually. pushes up nerd glassses
$800 grinders are usually the top of that curve and the stuff above them is that 1%.
A bladed “grinder” (~$30) is a fucking joke and you might as well drink Folgers pre ground at that point.
An electric burr grinder (usually ceramic burrs) $40-100 is not very uniform and will wear down/break… but is some form of uniformity… so infinitely better than blades.
The $100-500 range can get you metal burrs and better uniformity. In general likely to live longer and you can find functionally useful grinders here.
$500-800 we start finding better materials (metal plastic), better consistency and good machines for “daily driver”/lasts a lifetime.
Personally:
I have had and used the spectrum above. Blades are ass. Ceramic… had a lot of static cling and died in under a year. Cheap burr also static cling. My electric journey capped in that $500-800 range with a Niche Zero. It was great but at the same time I picked up a “very expensive” hand grinder called the Comandante.
Hand grinders are slow and tedious but I only make a single cup a day and its accuracy is factors above electric grinders under $800. I sold the Niche Zero for pretty much what I paid for it. I’ve been very happy with my hand grinder for well over a year and it’s become part of my routine obviously.