Exactly. The only time you should really use bondo is when filling gashes in plastic parts. Shaving requires the door open mechanism be relocted, usually to the underside of the car. With the complexities of the central locking Im sure just the labor on shaving would be very costly compared to other cars. After that, you still have to consider your paint. For a better match, they will paint the entire midsection of the door, which using good paint wont run cheap.
<span style='color:gray'><span style='font-family:Courier'>1995 e36 3 Series RIP
1999 e46 3 Series BURN IN HELL
2000 MR-S Roadster= Current</span></span>