I am strongly opposed to more laws that seem to address a problem, but restrict the free market. Especially when the assumption is that the "government" is more ethical or even more responsive to the public.What that says to me is the company has something to hide ie usually they're selling the same product as can be obtained elsewhere for a lower price. As you're the manufacturer, that may not be the case here, although there's always the possibility that a reseller is undercutting the factory retail price. However either way, it stops comparison and that makes it a shady practice in my book and one I'd like to see outlawed in the UK at least.
Last year, I tried to help the community by providing a North American distributorship for a well known CN laser manufacturer. What I discovered was that they were selling the wholesale product at significantly different prices to different distributors. This made it impossible to resell the product AT COST for as low a price as the other well known CN distributor was able to RETAIL the product for. Nevertheless, there should not be any law preventing this other than the law of common sense. Maybe the decision to have distributors and support them is not necessarily a good one now that the globe is so inter-connected. I recently bought some pretty sophisticated meta-materials from a manufacturer in CN and my son purchased a radio amplifier from the builder in Denmark. These items are not, to the best of my knowledge, even made in the US or if they are, they certainly are not easily found.