Integrated Tube Amp approx. $2,500

I second the Willsenton R8. You can buy, sometimes, direct on line, I bought mine as an open box for under 1k delivered. Many option with tube rolling (of course), and operation mode, and simple bias adjust. This was my first "quality" tube amp, There's no reason you can't grow along with this amp. I believe The British Audiophile has an R8 in his stable.

I have the Wilsenton R8 in my living room. It’s been in use roughly two years with zero issues driving my old Dahlquist D30’s and a sub. No noise, original tubes and sounds amazing. A lot of times while listening I forget its price point as I just get lost in the music! 

Not sure how many hundreds you're willing to give, but I second the vote for a Cronus Magnum by Rogue Audio. 

Elekit, TU-8600S 300b Power Amp - nothing better and I see one on the "other site" actually connected to what I believe are Klipsch Cornwalls. This amp always gets incredible reviews.

Skunkie Designs Electronics did an extensive series of tear downs and reviews on both the Willsenton R8 and the Muzishare X7 over a period of months. It seems Willsenton took some of her feedback to heart and changed a few things in their circuitry to make it better as she suggested.

Here is a link to one of her videos. But note that there were other ones later where she applauded Willsenton for upgrading their design for safety.

Even so, while she liked both of these at the end of the day (after mods) she stated that well, nothing in life is free, and the quality of the transformers on tube amps means about as much as the quality of the tubes. Neither one of these is a "giant killer", but they are nice at their price points. Many people have bought them and enjoy them. 

https://youtu.be/fjGefU2qB-0