The cost of carburettor of Yamaha Alba 106 can be inquired from your nearest Yamaha service center or a spare part dealer. The bike has been discontinued from a long time and getting the spare parts would not be easy from a spare part dealer. You can ask the Yamaha officials as they can even bring the products on order, if the same has been manufactured and available in their stock. They can even suggest you for an alternate as most of the bikes share parts with each other in a single brand and you may use the carburettor of some other Yamaha motorcycle.