I'm a window cleaner and I do gutters. When I work by myself doing Windows I make $50 an hour, I figure that gutter cleaning is kinda "dumb" work, meaning it's easy and doesn't have to be perfect like a window. I charge $40 an hour for it. I'm doing one this week for $150, it'll only take me two hours, it's just really high though. It's all an add on though, I don't market gutter cleaning, I just do it for window clients. They already trust you and know that you do good work, so when they say they like a quote on gutter cleaning they will most likely give you the business as long as your price is reasonable oh, that's just my experience.