Here is a used Leben C600 under $4K you can't do much better than that as tubed integrateds go.
Tube Integrated Amp Recommendation
I am looking for a tube integrated amp that has lots of tube flavor (can't find a better word). I don't care for more modern tube amps that start to sound a lot like solid state. I need at least 25 watts, and my budget is $4K. Right now, I am thinking that Unison Research Triode 25 may be a good choice. I know that some vintage amps may work well; however, I don't have the time right now to pursue any restoration or maintenance needed to make them sound their best and keep them reliable. Any suggestions you may have are very much appreciated.