You should be able to get a used 51SE for about $2,600-$2,700 today with moderately new tubes (less than 500 hours max and 90%+ life remaining).
The 51SE is definately going to provide an upgrade over the 3xi you are currently running and the difference in price between the 31SE and 51SE is tiny (a few hundred dollars at the most), making the 51SE a lot more logical.
I recently bought a new preamp (this week), the 51SE was on my short list. I was offered one at $2,700 (seller came right out on my first contact that he would lower the price to that level) including shipping about 2-3 weeks ago - but I decided not to go that route.
Having owned BAT preamps and amps in the past, the one thing I never liked was how quickly their products lost value.
The 51SE is definately going to provide an upgrade over the 3xi you are currently running and the difference in price between the 31SE and 51SE is tiny (a few hundred dollars at the most), making the 51SE a lot more logical.
I recently bought a new preamp (this week), the 51SE was on my short list. I was offered one at $2,700 (seller came right out on my first contact that he would lower the price to that level) including shipping about 2-3 weeks ago - but I decided not to go that route.
Having owned BAT preamps and amps in the past, the one thing I never liked was how quickly their products lost value.