I think they put some of the bbags on sale this season, but not the leather motorcycle bags. some of the fabric, ponyhair and offshoot designs went on sale. or are on sale, as their big winter sale is going on right now!
give them a call- I know that all their chloe went on sale, but balenciaga moto leather bags never go on sale from them. I think the less popular colors from S/S 06 went on sale at Barneys though this season.
Last year, they had a few B-bags on sale for 50% off but they were not your ordinary moto bags. However, they did put that hideous neon yellow and green fabric City bags on sale for 50% off at one time. They also had a few pony hair coin purses for sale a few months ago too.
Basically, you won't find them putting the regular leather moto B-bags on sale anytime soon.