Cam Belt Failure

Hi Everyone, I'm simon1967 and have just joined the forum hope you can help. We have a Renault Scenic Megane (Fidji) 1.6 petrol on an 03 plate, its done 83000 miles. I'm pretty sure that today the cam belt has snapped while my wife was driving home, the car stalled and couldn't be restarted (luckily this happened a couple of hundred yards from our house and not on a busy road), it stalled while she was turning a corner and wasn't going very fast. Could the stalling of the car possibly be a different fault or is it pretty certain that it will be a snapped cam belt? There was no warning light or noise that she can recall. If it is the cam belt am I looking at vast amounts of money for a fix?? What are my other options?? Would a replacement engine be a cheaper option? What would I have to take into concideration if I go down the engine replacemente route?? We are not financially well off at the moment what do I do?? Any help would be greatly apreciated.