I have not experienced it and no, I don't really monitor their prices but I do comparison shop with two other suppliers to see where I could get an item for the lowest price.
Maybe you should ask your Wpac salesperson what's going on?
I have found that a lot of dealers charge more than the suggested retail price to their service customers. Not by a enormous amount like 40% but more like 10-20% I'm guessing. I do the same and my customers don't complain about it.