It is always wise to get a roof estimate costing done by a contractor. They are in the business of laying roofs and know exactly to take all the measurements and getting at the correct requirement of materials and labor for roofing. This will prevent any rude shocks to you in terms of cost after you have begun the work.
The prices will differ based on type of roofing that you want to install. Metals cost the most but they also last a lifetime. Copper, aluminum and steel are some of the metal roofs that are used. Metals are long-thinking and they look great too. Copper especially undergoes a slow oxidation process where it turns from golden to green over few years.
Asphalt is a popular choice in roofing. This is also long-lasting and lasts over 50-60 years. It is also recommended to get a few extra boxes of the roofing shingles to replace the broken or cracked ones. Else, you will have to hunt around to find the same kind of shingle which you have used in your roofing. Most manufacturers will keep changing their designs and materials used to keep up with the changing tastes. It's almost impossible to get the same type of shingles a few years down the line.
Do not go for the cheapest roofing shingles as this will end up becoming costlier as you will need to replace them quite often. Not only will you have to pay for materials but also labor and time. So, choose materials that come with warranty for a reasonable length of time. 50 years is a good number to aim for. Having to replace roofs every 10 years is not every ones cup of tea. Without you enjoy this kind of redesigning your home's look every few years it's not worth it.
There are hundreds of options available in roofing shingles choose something that is long-looking, looks good and meets your budget.