Best Options For A Tubed Preamp - $2500 Or Less, Preferably Used To Maximize Value

Used Modwright LS100 . Right in your range, excellent pre. Great company

The ProJect Pre Box RS2 Digital is a balanced preamp with a selectable tube output (or solid-state if not selected) with multiple selectable filters, a headphone amp, and dual DAC (ESS Sabre Pro 9038). It has a small form factor. New it is a little more than your spending target, used, a little less.

The Schiit Freya+ is a balanced preamp with selectable tube section (giving 12dB gain) that uses 6SN7 and other octal tubes or available solid-state LISST octal modules in its tube section, It has also a buffered solid-state output section and a passive no-gain section. Its form factor is table-top, due to the tubes extending partially out of the metal housing. Price new about $900, used less, excluding LISST or tubes, which are additional.

If you you are lucky, you can find a PrimaLuna Evo400. Great tubes to start. Better with NOS tubes. Easy to play with. Reliable. People will often discredit without having experience with... just because designed in Netherlands but built in China. That is actually what wakes it an amazing deal for the quality of components. It has balanced ports too. I upgraded to a Shindo, which is better, but not night and day, and at a price.

+2 On the Schiit Freya+ preamp

Mike

+3 on the Freya +. 
Mine with Ken-Rad VT231’s in the gain stage and CBS-Hytron 5692’s in the buffer is the best combo of tubes that I’ve rolled