What do you like in an inexpensive tube integrated

A Manley Stingray is my first thought, or consider going vintage. At well under your budget you should be readily able to find Fisher, Scott, Eico or Pilot integrated or receivers that have been recapped and brought up to original specs. You might also want to factor into your budget the cost of tube rolling. Good luck!

I've been very pleased with my Audio Space AS-3i integrated. Its price new is about the same as your budget. They are rare on the used market though. Re sonics, there's a review in the back issues of UHF Magazine and I agree with what they say.

Cayin is the way to go, great sound, great value.