I just bought one of those Monoprice / Stage Right / Harley Benton 15W tube amps used for $150. I am very impressed with the tones I get for the price. It has a Marshall JCM800-style sound to the gain tones.
I’m getting a good clean tone with the gain at 1-2, a nice Bluesy Overdrive with the gain at 4-5, and a nice heavy distortion sound with the gain at 8-9. The most interesting thing is that when I turn the gain up from min to max, I don’t really need to mess with the tone controls. Usually, I need to reduce the Bass and/or Treble controls as I add gain on other amps.
The only complaint I have is that the FX SEND appears to be too hot. If I turn the volume control up above 5 with any pedal in the FX loop, I get crackling sounds. A straight cable from SEND to RETURN or no connection, and all is well.
The plan is to eventually buy two of these and build a budget stereo rig. I just love the sound of panning delays, and I have a Boss RT-20 Leslie cabinet simulator pedal that should sound really good in stereo. 
