Fuel pump needs to be replaced. Approximate cost?

Part price determined by where you obtain it. Dealer very expensive, used on ebay, craiglist, or salvage yard cheap, from a parts store such as autozone or advance not cheap but not so expensive. That is something you can look up yourself on their websites. I would not buy a part from a saturn dealer unless there is no other choice.

Labor price at dealer very expensive, local shade tree mechanic cheap, local repair shop not so cheap nor expensive. I will not pay a saturn dealer to work on a car unless there is no other choice. However there are some repairs peculiar to the saturn wherein you want somebody to do it who has done it before. I would not put a fuel pump replacement into that category. I will pay a saturn mechanic for general engine diagnosis or to pull the dashboard but for little else.

Personally I stay away from used parts which are wear items, do you want to do this again soon? A window or door is not a wear item but a fuel pump is so I would go with a new one unless you just cannot afford it. Good luck