Tube amps under $7500

For the money, it would be difficult to do better than a Don Sachs Kootenai KT88-based amp.  A few are available at the moment. 

Look into AtmaSphere OTL.  Excellent amps with great customer service.

I would recommend an older Conrad Johnson such as a premier 140 used, Also, Manley Snappers, I’ve had great luck using both. They both will fall within your budget. Both of these amplify sound glorious. Good luck with your search. 
 

Michael. 

For $7,500 you can get a PrimaLuna EVO 400 integrated and swap the EL34s for KT150s. I did, and hear added body and slam, and a wider soundstage.

If you go with a pair of Atma-Sphere M-60's (a great amp, which I have owned) or S-30, for use with a 4 ohm loudspeaker you will need the Z-Music Transformer, which raises the impedance the amp sees. OTL amps don't like low impedences.