IMHO, most Martin Committees are way overpriced due to demand from players who want one even if their playing capabilities don't warrant such an investment...
I don't deny that there are wonderful instruments amongst those remaining with us; but it is a fact (as with all instruments) that there are some played-outs and duds amongst them and what's even more important, an instrument needs to be suited to a player's charactristics and typical repertoire. You would not play a Mozart Mass on a Committee, just the same as you would have your work cut out playing swing solos on a Selmer piccolo.
So, as with all instruments, only buy "into the dark" if you cannot really miss due to proven quality, known fittingness of instrument or good price.
I have several times bought "into the dark" because something seemed desirable at the time... with the result that afterwards, I either could not get to grips with the instrument, or it had some hidden defect, or it failed to fit a need I had. Result?
Neither of these instruments is with me now.
I'll explain:
As a relatively inexperienced players, I had a lot of recordings of music for the corno da caccia - and I had money to burn. So, when on a business trip to Leipzig, I casually wandered into Friedbert Syhre's workshdp because there was a beautiful silver-plated corno in the window, and bought it for cash (a whopping € 4,000). I practised on it once a week, perhaps, for about five years, never played a single gig with it, and then sold it to a guy who really could use it, for half the price.
A couple of years later, I found a Clemens Glier Kuhlohorn on e-bay; really wanted it as a rotary flugelhorn to complement my piston Courtois. Bid on it till the cows came home, got it, used it for about ten rehearsals and two gigs and then found that as a flugelhorn, it was unsatisfactory compared to my Courtois, and sold it on to a player in Vermont who can really use it in church music.
At one time, I was so completely kitted out that I virtually had a trumpet for every possible pitch (A, Bb, C, D, E - for Hummel Original [which I never played] - Eb, G). The only thing I lacked was a trumpet in F. So I, young fool that I was, ordered one from Vinceent Bach, silver plated. Took about six months to get to me; played beautifully; but then, again, I was lacking opportunities of using it. So after a year, I re-sold it at half price.
One more instance: I had a beautiful Besson Kanstul Bb/A picc that I really liked and which I sounded nice on. But I was dead set on having a Stomvi picc, due to the Maurice André connection, and sold the Besson Kanstul for a Stomvi Elite. Nice horn; but the valve block was built a bit lighter than the Besson, and it did not fit my hand so nicely which forced me to exert too much pressure on the valve block with the result that valve #1 regularly got stuck... something I had never experienced with the Besson I am using in this pic...
I'll continue with my success stories...
Found an oldish, almost worn-out Courtois Balanced Bb at Votruba's in Vienna for a price tag of € 300, had it refurbed for another € 150 and been playing it successfully in symphonic settings ever since all over Europe...
About a year later, in 2018, Votruba's called me to see a nice horn that just had come into their shop out of a trumpet player's estate... turned out to be a nicely preserved Olds Recording, for a mere € 450... has been my main big band axe ever since...
Hope you can make some sense out of my rambling!