In that price range, a used Hafler is probably the best
sounding bet. Any of them can drive a 2 ohm load, all day
long, at rated power. Having the power supply caps replaced,
on the older ones, would be a good idea. Type, "eBay Hafler
power amp" in your searchbar. This site won't handle the
whole url, for a link. Another nice thing about the Haflers;
they are a piece of cake to upgrade/tweak, should you get the
urge later.