What I see as the great downside of getting this kind of camera pre-built is, unless it was assembled *by Bender*, I'd be forever wondering if the fellow who built it did everything correctly. They're supposed to be better than the Aletta (of which I have one that I don't get much use from becuase the bellows isn't light tight, doesn't compress enough to focus infinity with a 135 mm lens or allow any movements with a 150 mm, but won't stretch enough to focus nearer than the horizon with a 300 mm -- I'll get it fixed up eventually), but so much is dependent on the builder's skill and ability to follow directions.
Honestly, I'd probably pay more for a complete Bender kit than a non-factory built-up Bender camera...