Yes, build quality. Ignoring the outer case, overall design appeal, etc. – the inner guts are either built well, or they’re not.

When you grind something between two pieces of metal, if the pieces of metal can wiggle or bend or move, you end up with inconsistent coffee grinds. Big boulders, tiny fines, and everything in between.

If the metal parts are rigid and uniformly spaced from the factory, then you enter the territory of nicely ground coffee. There are fewer outliers, and most of the grinds are of similar size.

This all translates into coffee that’s easier to brew because the water flows through it easier, and coffee that tastes better. The big boulders will be under extracted (sour), and the fine particles will be over extracted (bitter). The stuff in between will taste good, but the sour and bitter stuff might “ruin” it.

The Baratza Encore has been a go-to recommendation for years, and if you’re on a bit of a budget that’s what I would get. You absolutely get what you pay for with coffee grinders, so if you’re flush I would skip the Encore and get something 3x the price. “Buy once, cry once” as they say.

One factor that I don’t think I’ve seen anyone mention is that better grinders will have better motors that can run slowly but still break beans down with high torque. The cheaper grinders have faster motors at a lower torque, so they rely on high speed impact to generate the force necessary. That translates to much louder, and much more broken bits of beans ( fines)

Well, as with anything, there are a lot of things that factor into price. Grinders are not special in that regard. You could pay more for brand name; for where it’s made (US, Germany, Japan vs China, Vietnam, Mexico); more options, like more granular controls or automation; better quality materials, like better, quieter, or longer-life motors and plates; design aesthetics; glass and metals vs plastics; whatever. Some of these could affect grind consistency, and many won’t. I honestly don’t know how you’d tell outside of reviews on coffee-related sites. In general, I’d say anything made in Japan is probably still a safe bet; although most quality grinder companies seem to be Italian, there are still fewer sketchy companies in Japan than anywhere else.

I’ve never heard of Melita, but I’m not exactly an expert. Companies have long known giving their company a name similar to a name that sounds live it comes from a country with a reputation for quality it a field will increase sales. Melita might sound Japanese, but be actually made in China, or you might hear an French-sounding name used by a cheap American wine maker. Just review the company, see where it’s made, see if you can find reviews.

Incidentally, tyere are excellent quality Chinese companies, but few that are alse cheap. This is true for any country; you get what you pay for. I have a machined aluminum, high-power laser made in China. It is very high quality; it was not inexpensive. So if your $15 grinder is refurbished, or lightly used, and it’s far more expensive new, then sure. Why not? It’s not much of a risk at that cost. But if that’s the cost new, then hard no. I’d not risk money on any grinder less than $70 new, and $100 if you can stretch that. There’s only so little quality materials cost. Like I said, refurbished is a different matter, and can bring the cost down.

I will add a caution about used grinders, though. The nature of grinders is such that it’s easy to use a grinder in such a way as to damage the grinding plates. You never want metal-on-metal grinding, for obvious reasons, and most burr grinders will let you set the grind so that the plates are touching. If the previous owner misused the grinder, you could get a damaged one and not be able to tell unless you take it apart and inspect at the plates. If the company did a refurbish, they probably checked it (you’d hope). Do not accept Amazon refurished; they test products function and superficially clean them, and little more. Fine for maybe a Wifi router, but I wouldn’t accept an Amazon-refurbished grinder.