For what it's worth, you can buy Depo turn signal assemblies cheap as wine on eBay. I'm waiting for a left side for the eldest son's E300D to arrive right now, as his just popped off the car, which happens as the plastic of the retention tabs age. He was convinced someone vandalized his car until I reminded him about the last time we changed bulbs and how brittle the plastic tab was.
I think it was under $30 for a new one. He's on a budget, so I have no druthers about putting something like this on his car (I do not own the car, I procured it for him and he paid me for it.) It's a matter of economics and function in his case.
Dan