Obviously, those aren't genuine Playmobil stickers. As for the price, it depends if it's printed on photo paper or vinyl. Photo paper prints will quickly fade and are qute fragile too, whereas vinyl's much better looking, colours don't fade and it's easier to apply on the ABS because it's waterproof and you can use soapy water to adjust the sticker correctly! So if it's vinyl, and the def of the designs is good then it's almost worth it.
Cheers.
Arnaud