I’ve had my 2009 30i since May 2019 and apart from annual servicing, one new set of tyres (although this wasn’t necessary I just wanted rid of the runflats), front and rear brake pads and rear discs it has cost me nothing in other repairs. I bought it with around 30k miles and it now has 60k miles. The N52 is a great engine, silky smooth, sounds great very reliable and on long runs pretty fuel efficient too.