From what I know, it's very similar with APC here. Besides buying APC direct with their insane online prices, even the official distribution channels give you higher prices if you come to them as a small business interested in reselling than what can you buy it for in retail shops. From what I heard, there is lot of stuff coming from Germany and especially Poland, where they often source it in large quantities for "projects" (where each corporation gladly provides some extra discounts) only for that to end in retail who knows where. So I would not really care, as long as the shop looks trustworthy enough and works for more than few months, it should be OK.
It's the same with components, servers, enterprise network devices etc., pretty much everywhere.
As I said, I'd stay away from the RS/Pro series. The Eaton Ellipse ECO is pretty much the same function-wise, there's not much to make up for the price. I have not heard about many bad Eaton units, though that may be just because they are not so common around here. Though their share declines, APC is still having the largest portion of the local market.