Where to buy transmission solenoids?

Where can a girl buy OEM quality transmission solenoids for my 722.6 (NAG1) other than the dealer? I have tried the $100/set copies from eBay/Amazon - although they look darn near identical to OEM, I had one fail within 2 weeks. The dealership is just too darn expensive.

thanks

Europarts sells them. They're still not cheap though, but typically their prices are less than dealer for OEM parts.

Have you checked ID parts as well?
https://www.idparts.com/mercedes-shift-solenoid-2402701600-p-10159.html