I bought my car used, and it came with a missing left rear lock piece, the piece that sticks up and out of the door.

This is obviously what it normally looks like:


This is what my left side rear lock looks like:


I went to the dealer a year or two ago to see what it would cost to put one in. I was quoted at $8 for the part, and $70 for the labor WTF...The labor fee has now gone up to $88, and I am definitely not getting it done there. The reason I need to go to the dealer is that our lock pieces taper out at the bottom to prevent someone from simply unscrewing it and stealing it. But of course that means that to take one out or put one in you have to take apart the door. I think I'm just going to buy a gray Honda lock (instead of the tapered Acura lock) which is not tapered at the bottom and I can just screw it in. Does anyone know what the part number would be for such a piece? I'd assume the dealer would be the easiest place to get one, but do you guys have any other suggestions for places to look?