My wife is an RT, and I know all the challenges of being one vs. being a nurse. RN's do make more money, but it's negligible. And, when you consider the amount of stress and work you are doing, it doesn't make sense. You will be doing twice the work load but get maybe 10-15% more pay. However, as an RN, you will have much more vertical and lateral oppty's. That's a fact. There also may be more jobs, but remember, there are WAY more nurses too.
Right now, my feeling is there are equal RT and RN jobs out there when you consider the market supply. My wife was a supervisor, and she said there weren't a whole lot of applicants for their jobs. She also said you CAN get RT jobs even nowadays, but YOU MUST BE WILLING TO MOVE. As long as you move, you will have no problems. It's not as bad as RN where they require at least 1 year experience nowadays for any job.
Finally, just read all the threads about new grad RN's having a hard time finding jobs. It's a tough job market out there for health care. My wife has been saying this too. The conditions have stiffened up drastically. I remember back in the early 90's, nurses faced similar job market conditions as well. I remember several older nurses at my school tell me that it was not a good time to go into the profession. Anyways, I'm just telling you this in case you decide on going into nursing with the expectation of having a job when you're done. It might not turn out that way. Just read the other threads.