I do not think so.. mid-range lines like Coach, Rebecca Minkoff, etc. have established themselves as affordable luxury and would struggle to become more high end. What usually happens is a mid-range brand will try to acquire a high end brand. This is evident in the recent rumour that Coach is trying to acquire Burberry. An acquisition like this would provide Coach with instant access to the upscale market.
Apart from the brand association ... I have always felt that you get what you pay for. Mid range bags can often do the trick and achieve their functional purpose, but the quality, construction, details, and durability often comes only with the higher end bags.