not sure why they'd be cheaper, i have assurances that they weren't over revved before the 1200m service, which was obviously then done to spec too.
Let's face it, any Z4M is going to be thrashed hard once it's safe to do so, whether it's by the press or the first owner.
But yes, I got mine at 1350 miles with all the correct history and it's never missed a beat.
I did wonder when I first looked that there were marks on the wheels where weights had been previously, and wondered why it may have had a second set of tyres at 1300 miles, lol. 8)