Roofing is a tricky thing, as the quality & knowledge of a roofer can vary greatly - how many roofs are already installed, does the old roof need to come off, what is the sub-roof condition, what is the flashing around chimneys, dormers, gables, etc. How a new roof can provide value to a home is also dependent on the quality of the roofer, their warranty and documentation - including permits. In general, the roofing trade has been reduced to small margins that are mostly made by minimizing the labor portion of the trade - materials are a fixed commodity. There are a 100 roofer's in the area - most aren't what they say they are. As a real estate professional in Darien, many clients have required various trades to repair or upgrade their newly acquired homes. I would be happy to provide a few references that may help your situation. No obligation, just let me know.
Stephan von Jena
William Pitt Sotheby's International Realty
1057 Post Road
Darien, CT 06820