It has been estimated that most homeowners tend to spend between $700 and $1,700 with an average of $1,100 for their sump pump installation in Seattle. Many factors can affect the cost of your Seattle sump pump installation such as the type of pump, the kind of flooring that you have, the location of where the pump will be installed, and your geographical location. There are two major types of sump pumps available today: the pedestal sump pump and the submersible sump pump. A pedestal sump pump can last for up to 25 to 30 years and it can cost you around $60 for a conventional 1/3 horsepower pump up to $200 for a ½ horsepower pump. Submersible sump pump, on the other hand, is estimated to cost around $100 to $400 with ¾ horsepower. However, its lifespan can only reach up to 15 years maximum.