This is listed as a "Martin" but is actually a Conn. It is in very nice shape based on photos. Conns typically have a very pretty tone, along with good response and intonation. Nice hard case included. Starting bid is $100 and the buy-it-now price is $160!! THAT is a bargain (or a typo)
SOLD FOR $160 - SOMEONE GOT A GOOD DEAL!
https://www.ebay.com/itm/The-Martin-Band-Instrument-Co-3-Valve-Euphonium-Tuba-Elkhart-Indiana/312850406316