This sounds a lot like an x-y problem.
Incidentally, getting lots (>>gigabit) data from A-to-B for cheap is the field I'm working in, so perhaps I could help with some outside-of-the-box ideas if you can give more information/limits you are facing. What volume are you looking at?
Depending on what output type you have, you might be able to do something with larger symbol size? instead of OOK, consider 4 or even 8 ASK to lower symbolrate?