I have seen how sketchy the LED lighting market can get and that alone is a good reason to go with the dealer. At least for one its a reputable source and if you come across problems in the future getting it resolved will be easy.
I was thinking about it as well, but I am opting for aftermarket LED lighting in my fog lights. As I understand, it's just the bulb they're changing out and the housing is the same. There are several contenders (available on Amazon); all with good reviews and warranty.