My 2014 F10 530D came with Bridgestones as standard fitment.
Price seems about right, I paid a little more for my 530D M Sport from Sytner BMW with 11000 miles on the clock.
First service should have been done by now I'd have thought.
As you say, check the tyres. Paying nearly £30k for a car I wouldn't accept different tyre brands on different axles, also ensure any that have been replaced have been replaced with RFT tyres
Good luck and enjoy!