Ford Focus ZX3 camshaft belt

I have an 03 FFZX3 that I bought used with approx 125K miles. The maintenance
book from Ford suggests that at 120k the camshaft belt should be replaced. The quote
I got from a local Ford dealership, parts and labor included (they suggested I should
change the water pump at the same time, which seemed reasonable) was over
$1500.00!! The car is in excellent condition and runs well, and I would like to keep it as
long as possible, but I only paid $4500.00 for it. $1500 seems excessive for a drive
belt. So here are my questions:

1) Is there any indication beforehand that a camshaft belt is going to break?
2) Is it common for FFZX3 camshaft belts to ever break?
3) If the camshaft belt breaks during operation, does it do any other damage to the
engine, or will I just be out the $1500.00 (plus the price of a tow)? In other words,
should I just drive the car until (if ever) the belt breaks?
4) Is this a reasonable price? I have the parts/price list if that helps.

Thanks!