I have a 30 ft Carver Aft Cabin with 18 X 17 props. Is it worth the expense to have them tuned? I think it will cost about $500 to have the job done. The reason I ask is my dock neighbor has it done every 2 years and he said that it will pay for itself in increased efficiently. Also there is no unusual vibriation. We are planning on running about 200 hours this year.