2003 Dodge Neon Question: Should I replace my catalytic converter or get another car?

My Dodge Neon has 108,000 miles on it and I've been driving it for three years. I still have another year left on the loan. I have to either have the catalytic converter replaced so it can pass state inspection or get another car by the end of October.
I've already had many repairs done on the car. In the spring of 2011, within six weeks, I had to have the transmission replaced (twice), the rack and pinion replaced, rear brakes fixed and a fan in the air conditioner.
I've also had to replace tie rod ends, front brake pads and rotors and rear struts.
At this point, my car is worth about $1400 at most and I owe $2500 on it. It will be paid off by October of 2013 but I'm worried about how much more it will cost me to allow it to make it that long. Would I be better off getting the catalytic converter (which I can't afford right now)or trading in the car and rolling the balance of the loan into a loan for another car?