They're a tick over $100 each from
TheBMWPartStore, which is about the cheapest place on the net.
That's probably going to be your best bet. Few people would be removing ones that weren't already broke.
I had to replace both of mine and the diaper right after I bought my car.
Previous owner must have had a steep driveway.
BTW, according to RealOEM, my 2006 MR doesn't have parts 23-26.
I don't know what the deal is there, but you may not actually be missing them. Maybe you never had them.