The most expensive trumpet to have gone at an auction was one used by Dizzy Gillespie, quite appropriately named the Dizzy Gillespie Martin Committee trumpet. It sold for an impressive $55,000 dollars. However, the most expensive trumpet that can be bought brand new is the Yamaha Platinum Trumpet, which cost around $125,000 dollars when it came out. From all research available, this particular version is no longer available.
However, Yamaha still has quite a few platinum trumpets available, but the price range is closer to $1,000 to $3,000 dollars these days. The original one was completely platinum. These new ones most likely have a silver or some other kind of metal in them so that they’re not quite as expensive.