Brake overhaul ? What do you mean by that ? resurface rotor and install a new pads ? or replacing a brake fluid ? I'm not familiar with the word overhaul - sounds to me like "we do nothing for a lot of money".
Ask him what is he wants to do and then decide. A rotor resurface is $8.00/pce at any local auto parts store. Brake pads are about cca. 55-120USD depends on what brand. Replace a fluid in a 8 series not as easy as any other car but rarely needed since the fluid is synthetic and has about 5-7 years as a lifetime. I replaced it at 100k miles in my old car and not a big job, but anybody can do it for about 40USD at a good reputable shop. (Even the stealer can do for about 60USD)

By : Lez

BTW : Where are you ???