I am fortunate to be doing both, but I will definitely say that if I relied solely on my reptile breeding to make a living, I would likely be resorting to feasting on road kill! I would pursue a fulltime career of interest, and then select some taxa that you have personal interest in and begin slowly trying to successfully breed the animals you are working with. And then slowly start adding more breeding projects as you have early successes. I would be more worried about finishing your B.S. and then seeing where things are at.