I have a 2007 Johnson 15HP 4 stroke on a 14' modified V Alumacraft jonboat. The manual says I need a 9-1/4X9 prop. That is the prop I currently have (Aluminum), and I am satisfied with the performance . I just damaged the prop and need to buy a new one. I am confused by all the brands and the wide range of prices. I saw a prop here on Iboats for $50, but I see some as much as $100. Are there differences in the brands from a performance or quality standpoint? Thanks.