What are the Bing carbies on the Jabiru like - expensive?
George ( down under) 

Jabiru Bings are 38mm butterfly/CD piston carbs. They work fine but lose about 5-6 hp compared to a slide carb and Posa, Revmaster fuel meterTBs like Ellison.
I have seen Bing CDs on ebay $200 and up. Easy to tune.
I believe that the Harley crowd use them on the hogs, and Rotax also use them on the 912/914 engines.
Dave