What is the general cost of a sump pump?

it depends on what you mean build you can go to Home Depot and get a sump pump for around $100 for mid level if you mean cutting the hole in the basement floor (concrete) it can become very expensive if you hire someone to do the work but if you do the work yourself you should be able to do it for between $100-$200 and only should take a couple hours (make sure to check codes in your town/city) good luck