Before I answer this question, I think you shouldn't post 6 threads in succession, I suggest that you just ask all of your questions in one post.
04 and 05 bags have amazing leather, way better than 06. Some 07 leather is really beautiful, some not so much.
As far as black goes, there have been some concerns about black 07 bags fading to greenish tints, and if you want more info on that, I suggest you use the search function and type 'black' 'faded' 'green' into a Balenciaga thread specified search.
04 and 05 bags are still very popular.
And you can buy the bags wherever you like, just ask the SA to pick a bag with the kind of leather that you want. No one place hoards better quality bags, and quality is in the eye of the beholder, some people like marbled leather while others want smooth, it's what you want.
Jaune and Violet were the most desired colors of this season.
Next season, Electric Blue, Turquoise, and Magenta seem to be the front-runners and no the 08 bags are not out yet, I spoke to BalNY on Thursday, theyre expecting preliminary shipments in 3-4 weeks.
