If you live in Germany here's your cheap three banger

[fairweathertuba]

It looks totally playable, also sort of Rudy like in the bell flare.

[chhite]

That horn was my former pastor's horn in Heidelberg. It's a Russian tuba (St. Pete before they were known by that name) with three clockwork sprung valves. It ended up going to a young German trumpet player that wanted an inexpensive instrument to learn.