I am going to throw in 4 to the mix. All different:
1. Gato Audio. To get to the budget you have look at their DIA 250. Used. This is class D. I have their AMP150 - Class AB. From Denmark.
2. Hegel. Again for your budget I would say H390. I think from Norway.
3. Vincent Audio. From Germany. I have SV200. It is their smallest integrated- hybrid. You could look at some of their other models. They are affordable even new.
4. Akitika. This one is a curve ball. Made in the US. Usually a DIY amp but also available fully fully assembled. I acquired one recently - assembled- with volume control. It works like a dream. Very very affordable- around $600. You would be surprised.
regards,
Manu