WoW a different question for a change.
The choice is very personal. It has a lot to do with where you see yourself playing.
There are a great many people who feel the need for 2 Bb’s. A good lead horn with some sizzle and a more mellow heavier sounding horn for more serious playing.
If you are a lead player who also solos then a Firebird might be a fun purchase.
A C trumpet comes into play if you see yourself playing in a symphony a great deal. It also comes in handy for church players who don’t want to transpose. (Shame on you.)
A cornet would be a choice if there is a brass band nearby or you get the Dixieland bug.
A flugel would get some use in a jazz band if you held the hot seat otherwise it would never come out of the case.
Another interesting jazz band piece would be a slide trumpet (cheaper than a firebird but still adds a new dimension).
A bass trumpet would be useful for some solo work in a jazz band if the bone players are weak.
A piccolo for wedding gigs or as a symphony addition only after a C.
An Eb, D, F…. only if you make your living with the trumpet and have all of the others first. p>All of these should be quality horns and not beginner quality horns. If however you were to go the used route you might shop wisely and end up with 3 for the price of 1. Or you might just take a nice vacation instead.