I buy all my parts online.
For my tractor, side by side, zero turn, motorcycle, Etc. I have never been back to the dealer to buy a part for any.
All of these replies are making me feel a lot better for doing what is right for me. After all, the dealers are doing what is right for them. They have no loyalty to me. Messick痴 is a brick and mortar dealer and can sell on line for much lower prices than my local dealer. I conclude, markup % is a dealers choice. If they make less on equipment, they will make their money on parts and probably service.
Please keep the comments coming.