They are good kits, I'll probably end up keeping them for myself to be honest. Although I can get a very good shipping price to US and Canada for them *cough*.  

I think they would sell too, just not in high enough numbers to make the development worth it. If you had a smaller company make them the price would higher at retail but the problem could be the project will take much, much longer to get off the ground and risks cost over runs or even fizzling out for a lack of interest. 

There are possibilities, however, I am looking into purchasing a 3D printer to play with, this has the potential to allow me to prototype parts myself and perhaps in the future rather than releasing complete tanks we might be able to release parts kits such as wheels, track links etc for scratch builders.