The amount of RNT'S and Echoes is definitely in correlation with the huge numbers they have sold to the masses
You're missing the fact that RM sells a ton. His custom runs sell out in 2mins or less. The prebuilt calls sell pretty fast as well, and especially special colors. Probably not as many as RNT or Echo, but they have a 30 year head start on him. Not to mention a slew of employees to crank them out. He's come very, very far in a very short time.
I only have the one RM call, and it's must likely they only one I'll have. So, I'm far from a fan boy. I've got way more calls than I should have already, and have no reason to by more. The one I did get is quite good. I prefer, the DCX I just bought to it though. I've always liked Daisy Cutters, so I guess that's no surprise.