Google doesn't charge you to use Android and Mozilla doesn't charge you to use FF OS. So how will FF OS be able to deliver cheaper phones?
It seems if they are able to bring down prices by introducing this "no-contract cheap phone option" into the market (which may be a good thing), then nothing stops the same exact manufacturer from releasing the same exact hardware running Android for the same exact price sine the OS doesn't play into the cost in either case.
I may be wrong, but I seem to remember that Google does charge the companies that build these devices, so that cost is propagated somewhere to the consumer.
However, the real cost saver is the fact that, in my experience, FirefoxOS largely outperforms Android on many tasks, and generally is usable on hardware that is much cheaper than anything Android requires to run these days.
It seems if they are able to bring down prices by introducing this "no-contract cheap phone option" into the market (which may be a good thing), then nothing stops the same exact manufacturer from releasing the same exact hardware running Android for the same exact price sine the OS doesn't play into the cost in either case.