It's a good practice to routinely inspect your roof for damages. If you catch a problem early it will save you money when it comes time to replace your roof. A roof that is in poor condition may have other issues that will effect the cost of the roof replacement. If your roof has allowed water to infiltrate through the layers, you may have water damage in your attic. If that is the case the roofing company will also have to replace any sections of rotted roof deck.