I bought a new euphonium, a Willson 2900 S. It's a four key, compensating, upright, silver (shiny) instrument, with some amazing craftsmanship. I got it on ebay from Mathews Music in Holland for 5k$ including shipping. I've doubled my roommates' ration of obnoxious tuba music.
I took the new euphonium to Ohlohne Tuba Ensemble rehearsal yesterday. The horn was a treat to play. Everybody there has really nice horns, but the Willson is among the best of the best. One fellow who I believe plays a Besson said that the Willson is the Swiss watch of euphoniums. Looking and feeling the craftsmanship and feeling the tolerances, I would have to agree. It's an amazing machine.
I finally grok what "compensating" in "compensating euphonium" means: I no longer have to "compensate" for the sharpness of every note between E flat 2 and pedal B flat by fingering them one half step lower, and I don't have to bend down to the B natural from C. The horn just has a continuum of chromatic pitches all the way down with orthogonal fingerings with those an octave higher on a three key horn.