In reply to Wee Davie:
My understanding (no legal knowledge) is the manufacturer can impose terms on their retailers to protect their brand image, etc, etc. This can in theory include pricing structure. Don't know if it is actually written in contract but if small retailers don't go with it, they will not be able to get the supply.
One well known outdoor clothing brand did this for 20+ years and particularly by refusing to supply larger chain retailers so as to keep prices at or near the RRP (or so I was told by many independent shops). Seems to have opened up over the last few years but the larger chains only have some of the model range.
There are many ways for manufacturer to control the market, whether actually legal or not, if their products are in demand.