Tube amps under $7500

@hotei  Integrateds have not ben on my radar, partly because failure on one end renders the other useless until repairs are made. But I must say, ARC for both pre and power at a reasonable price is a serious temptation. But then I wonder whether anyone would seriously recommend this unit with Legacys? 

Points well made and I'm not familiar with Legacy speakers.  However,  I pair a VSi75 with my Dynaudio Heritage Specials and it seems to drive them just fine.  And when playing vinyl have a Ref2 SE phono pre use a LOMC Lyra Delos and again seems to sound fine.  Of course I have a smaller room and moderate volume levels.

Audio Research i/50 meets your requirement for tube with balanced inputs and at the price point you mention.

@chenry Unfortunately, this unit is an integrated whose preamp section is not versatile enough for my needs. Also, its tubes won't deliver the current needed to handle the low impedances thrown up by my Legacy speakers. Seems the only tube amps likely to do this are the big ARC separates and the BATs with their monster output tubes. So I will be looking for a deal on one of those while pondering whether to just cave and go SS after all. Some are reputed to sound rather tube-y, or at least will operate in Class A to 40-50W.

Balanced is not differentially balanced. I am pretty certain that BAT is differentially balanced and I am not sure about ARC. My guess is not. Only makes a difference if your preamp is differentially balanced. True you can beat some speakers into submission with higher power, but you will not be getting the most from these tubes amps. It is not just impedance but also swings.