E550 seems a little much. They are very hard to find, but I don't know if I could justify that price point. I bought my G Rudolf Uebel, Reform-Boehm, for about $220. Granted, the bridge key is broken but that's a sub-$100 fix, placing it in the $350 maximum range.

I don't know much about these. I do know that they are pretty rare (at least in the US), and considered to be pretty good.

For your purposes, I doubt you could spend the $200 on a refurbishment (making it E750), and then still be able to sell for a profit. They're nice, but not THAT nice. 

Hello, I have a German system wooden rudolf uebel clarinet that I bought for 550€ and I'm wondering if it's worth that much. Were rudolf uebel clarinet good enough? Do I have a bad, cheap clarinet or a intermediate - Profesional clarinet?

I'll get you in touch with one of the country's preeminent low woodwind experts.

I have tried searching Sheet Music Plus, but my only findings were clarinet choir parts and parts in scores. Are there any good solo works for BBb Contrabass Clarinet? I own a Concert and Contest book for Bb Bass Clarinet, which I used to use for my Selmer Bundy Contralto Clarinet, but have also found the book compatible with BBb Contra as the highest note out of all the solos in the book is C4 (for a BBb with extended range to low written C). I have never experimented with the altissimo tones on my BBb. I just don't think I am there yet. I barely ever play either of my contras these days. I have been focusing more on getting better at Alto Sax. I would also like to try and learn the Bb Soprano Clarinet. I really like the way it sounds and its versatility. It seems like a great instrument to learn. I would be somewhat of a beginner, however; I am more experienced on the contra clarinets and Alto, Tenor, and Soprano saxes, and these instruments are much different than the Bb Soprano Clarinet. I own a Bb Soprano Clarinet but have to bring it to my local repair tech to have a cork installed on the middle tenon joint. It's just an old instrument. I would love to get it playable again so I can start learning.

Does the F1/C2 key pad seal over the tone hole completely? If this is not an issue, perhaps the Eb1 key pad or a side trill key pad doesn't seal properly?