If your like me and have a crawlspace or a basement then one good reason for a sump pump is to prevent mold.

I just had my crawl space get very damp and had a mold out break. It cost 1800 dollars a day to have the mold removel crew come in and remove it. Not to mention the items that have to be replaced and fix after. Removeing mold from your house is expensive.

Compare that to the cost of having a good sump pump and i think you will see the cost savings.