I would say that's a fair price. It's not inflated above the regular price and you do have to pay for shipping costs (not just postage - but the packaging, etc).
I agree with you, though. It is hard to pay full price for any Playmobil sets and I am not sure if I can remember paying full price for any sets. Well, maybe I did for my oldest daughter's 5300 but I bought pretty much all the furniture sets for about half price at Winners. Oh! I also paid full price for a whale deep sea explorer special set from Costco last fall. I have more time than money, so I wait.
Not to mention there is more Playmobil than I can afford so even if I only buy the sale items I can find then that's good.
I do find patience to be a virtue in practice, not just in theory, and it has paid off just to wait.