Usually, when we tubists bend pitches, it's on purpose. Usually...Tubas_in_the_moonlight wrote: On the notes I could hit okay, there was a noticeably "bendy" quality; I could lower and raise the pitch about a semi-tone each way.
Purchasing a tuba or renting one from a music store may not be your only options, either. I borrowed two different tubas (a fiberglass sousaphone for a short while, then a Yamaha upright for another couple years) from a nearby high school before finally deciding that I would play it often enough. That's when I scored a pretty good used tuba at a great price from a tuba-playing repairman friend.
If you find one that has all of its parts, doesn't leak, and isn't already beaten senseless, you'll be able to keep yourself entertained for quite a while.