E. One problem is finding the right contractor for your job. Then it's price and scheduling. The best
contractors tend to stay very busy.
Buyer beware: there are many roofing materials used, and many systems. They are not all equal. Each system has pros and cons, so doing a great deal of patient homework is important, unless you
already have your mind made up, or just want to fix and flip. Some systems are DIY and fast, others are technical, and time consuming. Even a badly done job may last many years before it fails (usually out of warranty), or due to faulty workmanship which most insurers don't cover for the contractor who installed it.
The most important references would be from owners of homes reroofed 10-20 years ago. Everyone
who's roof doesn't leak today is a satisfied customer today. It means very little.
And when you've made up your mind, don't hesitate to negotiate. There's no secret little rating system used to provide you a fair price. It's all about whatever an estimator thinks he can get out of
you. Much like buying a car.