I will provide an honest answer. I trust this will be appreciated. Please remember that a low rating PUNISHES me for being honest and that I receive nothing for my time until a positive rating is clicked.
yes, the better a car is looked after, the better buy it will be, that goes without saying.
it is true that the car does tell you when it needs a service. these vehicles are fairly light on maintenance.
if the one has only had 2 oil changes in 50,000 miles (not km) that is a red flag, but two services in addition to other oil changes would be totally normal
if the other has been in every 8-10k miles for repairs (as opposed to service) then this is also a red flag
I would simply advise that you invest in a pre purchase inspection at a main dealer or BMW specialist prior to purchase of any to have all systems and the engine checked out.
Please let me know if you have further questions. Please do not forget to click a positive rating as this is the only way I receive credit for my answer, thank you. Best wishes with your vehicle.