How much would it cost for an electrician to come and run an outlet ground wire?

I have a old two wire system in my house. I want to ground the whole house eventually. It's not really that big of a house only about 1,000 square feet. The outlet i want to ground is about 20 to 30 feet away from the breaker box and cold water pipe. I would like to know about how much it would cost to have someone come by and properly ground the outlet.