1994 Toyota Corolla Water Pump

In April 2010 I replaced my thermostat. In June of 2010 I replaced my radiator. Shortly after replacing the radiator my water pump began to leak. The car was continously driven after noticing the leak with no issues until the weather started getting colder. Now it takes a while for the heater to get warm. I'm assuming the water pump has a something to do with this and you can correct me if I'm wrong. My question is on an average what would the cost be to get the pump replaced. Reason why I asked is because I am have been deployed to Afghanistan since May 2010 and my wife took the car in to get an estimate on getting the pump replaced. She was told it was gonna be about $300 and that is not including the part. I felt that it was pretty steep being that I replaced the Power steering pump for around $180 to include parts and labor and it sits right next to the water pump. If you could give me an average cost of this part or just even let me know if my wife is being husseled I would greatly appriciate it. Thanks!