If I were looking for a hopper-fed grinder for classic espresso, the Eureka grinders would be high on my list, especially ones like the Atom 75 with Mythos-like burrs. If I were looking for a single-dosing grinder for classic espresso, I'd go with a Niche Zero.

Checking Buy/Sell here is one way to get a feeling for used pricing. The Specialita is, I believe $700 new. Using search, it looks like $450-500 is a reasonable, but not extraordinary price.

Is the workflow for single-dosing and in-cup quality of the Niche Zero at around $670 delivered $200 or so better than than a Specialita? I don't know on the second, most of the comparisons I have read have been with the Atom or other up-range Eurekas. On the first, it comes down to your budget and priorities. I could make up some hand-wavy justification based on "wasting" 5-10 g of coffee a day. The reality is that I really enjoy the smooth adjuster and not having to brush and vacuum out a grinder every day or between every grind change.

I've been using my Eureka Mignon ORO XL for about a year now for espresso, I bought it for 650 euros, I can recommend it. I single dose with it and there is a .1 variation in grams, if I put 18g in, I sometimes get 18.1g out or 17.9g out (there is some exchange of grinds inside the grinder). I kind of want to upgrade now but just because I realized that I'm more into light roasted coffees and the Eureka Mignon Oro XL is more suited to more developped roasts. For filter coffee, I prefer the Fellow Ode or my Comandante.

For $1000, you could get a Niche and a Commandante