I would think, that if someone were to experience this kind of problem, and as this seems to be becoming more prevalent among cars in the 8-10 year range, it would be a serious turnoff to purchase Mercedes in the future.
I'm not a huge DIY'er like some of my esteemed and gifted colleagues, and I don't mind paying paying $$ for legitimate repairs. FE, I can justify $1,500.00 - $2,500.00 for a head repair and reconditioning. However, $2,500.00 - $3,000.00 + for a SINGLE faulty component in the a/c system would surely be the kiss of death for me, and I'm sure other owners as well.
My solution is that I just buy Benzes that don't have a track record of blowing their evaperator cores, and if they do, one can easily get at them without disassembling 75% of the car!
Just my 2 cents, FWIW.