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

Line 2CRM Line Preamplifier from Mapletree Audio - An earlier version has been in my main rig for many years while I upgraded everything else around it. Fun to tube roll to get the sound you prefer.

https://www.mapletreeaudio.com/

My tube preamp journey started with a stock PAS3, then a restored PAS3, then a VanAlstine Super PAS3, then a Conrad Johnson PV5, then an AI M3.  

I now switch between an ARC SP-10MKII and an AI M3B.  Both are sublime, and can be found within your price range.  The AI is on the neutral side of tube warmth, the ARC has more warmth, but also better definition.

Biggest changes I noticed in progression was from a restored PAS3 to the Super Pas 3, then when switching from the CJ PV5 to and AI M3 (pre "a" model).

An AI M3 or M3a are true bargains, can be found for about $1k with some patience.

Schiit Freya+. Buy a pair each of NOS Tung Sol 6SN7 GTB and Sylvania chrome top tubes.

Done.

@nightfall 

+1 for ARC

I have went through many line stages over the past 5 years that included the LS 26 & 27.  I would not recommend simply looking at them in the sense of the number as your sequential options.  I would stay within a generation.  For example, the LS17 & LS26 and then the LS17SE and LS27.  The 27 was a significant upgrade over the 26 and the aesthetics are nice upgrade as well if that appeals to you.  I never had a 17SE but have always heard and read they were quite impressive.  

Like most of the top brands, these older models hold their value quite well.  I believe you could find a 17SE for around $2000 and an 27 for around $3000.  These prices haven't changed much in the past 4-5 years and won't likely drop significantly anytime soon for one in great condition.  This all to say, try one if you find it and if it turns out to not be the sound you are looking for...sell it.

Good luck!

CJ PV series pre-amps, Audible Illusions pre-amps for <= to 2,500.