I believe that Balenciaga changed their leather manufacturer starting with the 2005 Spring/Summer line.
Prior to that, the leather on their bags was superb ... the leather wasn't shiny or waxy, it was soft and buttery. The distressing was done so that it just looked like the bag had been lovingly used, not 'worn out' at the edges or anything like that.
The leather on the new bags is stiffer, shinier and in some cases, has a waxy finish. The distressing is more of a crackling versus a subtle worn look.
From what I've heard, so many people have complained to Balenciaga about the leather from the past seasons, that they are looking into going back to the original manufacturer. I certainly hope so.
When I return home after the Christmas holidays, I'm going to take some pictures of some of my older B-Bags and the new one so that everyone can see the difference (believe me ... you will be able to see it).
I think that is why you might be finding more B-Bags than before ... people simply didn't want to part with the bucks for the newer bags.
(The pony bags are flying out the door though!).