I live in east ga almost sc if that matters. My roof is about 8 years on. 20 year shingles. The leak is around my chimney. The plywood is rotten about 3-4 square feet total of rotted blywood around the chimney. There does not appear to be any drywall or ceiling damage. What should I expect to pay to fix this? Just want a general idea so I know the estimates I get are reasonable. Thanks