I got it in Harrods the Dior Clothing Boutique on the first floor, the ground floor bag boutique didn't have it and neither did the actually Dior store so I don't know how hard it is to get I just saw it there in the case and had to have it. It reatailed at £135
I just tried my LV Corsaire bag (it is REALLY heavy) and it seemed ok but I don't think I'd use it for really heavy bags just to be on the safe side