Looking for advice on whether it's worth the double price of going with Sherwin Williams Duration exterior house paint. I have the Masonite siding problem and want the house sealed good to avoid moisture problems. Also our house stands 45 feet high(it's built in a hill) so it's very difficult to paint and don't really want to paint any time soon. Is it worth it to spend $40 a gallon on Duration or just go with a good $20 a gallon house paint? Is the Duration THAT much better??????