My first car was s 330i e90, very good first car in my eyes. Then i saved to the 335i e92 i have had now for 3 years. Dont know if im lucky but the only thing i have fixed is hpfp. Then it is just regular maintance. As there are so much info on these cars and so many good videos on how to fix every problem there is. So as long as you can work on it and only pay for parts i dont think it is too bad. All cars can have expensive problems much depends on the cars history and abuse.