Installing a sump pump to prevent flooding and similar purposes is usually cheap enough not to require financing, with a national average around $1,200. Many factors can potentially push this higher, however. If the complete system, including the pump, drains, drain tiles, basin, and pipework needs to be installed, the price typically comes in higher, at $2,500 to $6,000. With very large basements or areas that require multiple sump pumps and extensive, complicated pipework, the cost can be anywhere from $10,000 to $15,000, or higher.