For what it's worth, I was in HK this April, I window shopped at a few of them, I did see a navy kelly that appealed to me, it was 37 years old and was pretty beat. (can't remember the store name but it has the word Tokyo it it, Tokyo destination or something, in Kowloon) Although it looked authentic, I dont even know how much repair H could offer it. They were asking the equivalent of a bit over $3000, (on sale but I don't know if it customary to say everything is on sale/mark it up to mark it down) I was looking at it for a while but not long 5 to 10 mins and they offered to get a manger's special price and dropped to a bit over $2700. I'm sure at this point i could've kept negotiating but i wasn't really 100% feeling the bag with all it's faults, and i would've wanted it under 2k for the investment I would need to add in repairs. I had a feeling it was just this stock that they wanted to move not all pieces were that negotiable but I'm sure they have a lot of wiggle room, even for birkins...
I was also looking at a chanel flap for my sister and they were willing to discount for cash, albeit that they only gave me a $30 discount assuming I was a naive tourist (which I was) it was still several hundered out of my sisters budget so i thought there was no point even attempting to negotiating any further