Builders Warehouse High Prices

Whilst one expects Builders Warehouse to have market related or competitive prices, on two random items I checked this week, their selling price was far higher than my local (and other) hardware stores. e.g. :- 1.Tubular steel J bracket Builders price was R89 and the local hardware was R60. 2. Woodoc exterior penetrating oil 1 ltr. Builders price R299 local hardware R215.