I don't know anything about the business they are directing you to, but an extra prop never hurts, like Cray posted. You never know when you are going to hit a stump or boulder or whatever. I have an extra prop now because I had to send in the original after I misjudged my distance from the garage and backed into it. I bought another prop while mine was getting repaired and it is a slightly lower pitch than the original. It works better than the original for skiing and tubing, which is how my boat gets most of its hours on the big motor anyway. And now I have an extra prop ready to go if I ever need it.