Sir nothing to worry about
as the saying goes ... "Sar salamat rahay, jutiyaan bariaan" ... 
About maintenance ... yes .. maintenance cost of BMW is far higher than a Corolla ... but who cares, when it is a BMW ...
BTW ... I have my eyes set on a BMW 740 ... yes. real BMW with four tyres, not with two legs .... lets see...!!! My mind tells me to stay away, but the heart ... it is attracted like a magnet to that beauty(H)