My oem bs's lasted best part of 60k on the rears. With my second mk7 when I got the fronts replaced the first time i got them to swap the rears onto the front.
So about eighteen months in i had decent tyres all round.
Although to be fair, the decent rubber on the front makes a noticeable difference, the rear less so but at least it didn't cost anything.
The dealer would charge you no doubt though.