Only if you can get them listed at Digi-Key/Mouser/etc. Even if it's under a "maker" brand like Adafruit, Sparkfun, etc. Anyone who can replacement TIL311 and friends displays in there, and advertise them, will sell quite a few.

They're not hard to make, but they're the sort of thing that no one really wants to make in-house, since they're a means to an end rather than an end in themselves. Great thing to sell, though!