The most common cause of annual mower repairs results from leaving gas or gas-oil mix inside the engine's tank and carburetor over the winter season. Avoid expensive service shop charges by either 1) running the engine until all gas has been used up, or 2) adding a commercially-available gas stabilizer to the tank before putting the mower away in the fall. A $3 investment may save you a $60 repair bill.
Shop during the off-season. Many heating and cooling manufacturers offer significant rebates during seasonal sales promotions, and dealers may charge less for installation.