The Noblet bass clarinet is practically identical to the Leblanc, other than a slightly different register mechanism (if I recall correctly) and corked-tenon neck rather than metal sleeve. Acoustically the same, and in my experience plays the same. Which means, some are stuffy and out of tune, some are just OK, a few are pretty good, but none are great.
Here's another thought: A used Amati, if you can find one. The fairly recent ones (post-Communist era) are pretty decent, and are priced in the Noblet range. Plus, they made low-C versions as well.