Opera Consonance Cyber 20!
You should be able to get one for that price - you certainly can if you order direct from PRC (mine cost RMB 2,800 new, that's about USD 440 at today's rates). You should budget for some NOS tubes, though (1x ECC82, 2x EL84). You may, of course, face import duty......
Sound is very transparent, with a huge soundstage and a sense of "architectural" solidity, combining the benefits of a transformer-coupled SE design with the "EL84 sound". There is a very slight low frequency hum, though, which is apparently due to the design of the output transformers (I've had mine re-checked by the manufacturer in Beijing, and it is performing to specification - they basically said "they all do that, Sir!"). So, not perfect, but an interesting product at the price, which works well with HD600s for classical and jazz.
At the moment, I'm using a JJ "gold pin" ECC82 and the stock output tubes (as NOS tubes sold in China are often fakes). The stock driver tube was of poor quality. I will pick up some "proper" NOS tubes when I return to the UK over Christmas (Mullard CV4003 + 2x 1967 Soviet Philips EL84 "Black Top" - all from Langrex), and will report again when it's all up and running.