I've just started in LMCE and I currently buy from Fiire, but I'm beginning to get interested in products/features they don't offer. (Webpads, alarm, video surveillence, etc.)
As far as price, everybody knows that you pay for convenience and reliability, I'm more than happy to pay more for products I can feel confident will work. I already have an IT job that keeps me busy 60-80 hours a week and I don't have the time to properly research product compatibility. The support issue isn't paramount to me beyond RMA if necessary, I know enough about LMCE to know that it's a work in progress and it has a ways to go to becoming a "supportable" product and I'm completely OK with that.
The store is appealing to me because it will hopefully be a one stop shop for everything I want to do with my LMCE installation. And I can buy with confidence knowing the products offered are proven to work with LMCE. For that assurance I'll happily pay above market price.