I think one of the root of the problem is that they are advertisted by the official mastercoin.org website, and thus seems like they are the "official" solution to buy mastercoins.

Personnally I have been pretty shocked when first studying mastercoin to see that the official ressources were advertising for a website that was selling at *4 the price, and it gave me a bad first perspective on mastercoin.

I am really excited on the state of mastercoin development and all the upcoming feature, but this does not shine very well.

Disclaimer, I will be launching a concurrent business. But my insatisfaction with the existing one is part of the reason we are doing it.