The issue with NB-IoT right now is chicken vs egg.
NB-IoT stuff currently is limited to expensive modules.
Why? Because the carriers aren't rolling this out yet and when it is it's expensive. So, nobody is going to make a chip for it since the volume isn't going to be there for a while (Intel, for example, just pulled out of making NB-IoT chips). So, the badly integrated systems are going to be battery hungry and expensive, which means that the carriers don't see any volume and consequently don't feel the need to work very hard rolling it out.
Once the carriers finally get NB-IoT stuff universally deployed (even if it's expensive) then the silicon vendors will go to work on integrating everything into a single chip.
Once that happens, someone will say: "Hi, T-Mobile, I have 10 million devices I would like to activate and connect. Would you like to do this or should I go talk to Verizon, AT&T, etc." and the prices will come down.
This will follow the same trajectory as cellular data vs cellular voice.