What do you like in an inexpensive tube integrated

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.

Audio Space is manufactured in Hong Kong. Cayin is manufactured in China. Manley Stingray is manufactured in USA. You can call and talk to someone at Manley if you need advice or if you need service. The Stingray sounds much more powerful than its rating. It has a big relaxed sound that you get from high powered amplifiers with delicacy and detail. It's a no brainer.

Rogue Audio Cronus Magnum 90 wpc - USA built, excellent customer service if needed, or simply for asking questions

I second the vote for Rogue Cronus