After market pumps go for about $150-350, depending on what you get.
A standard replacement is not too hard.
Open your boot, and under the carpet you will see a round cover plate screwed to the bottom left hand side of the floor.
Take these screws off and remove cover.
Clean away any dirt/dust from the area above the fuel pump housing.
Un plug power wires and gauge wires (2 plugs).
Loosen fuel line clamps, and remove hoses. Remember not to get these two hoses mixed up when your re installing.
You will then see a big circle plastic nut type device holding the pump housing down. Turn the anti clockwise to loosen. You may need to give it a good wack to get it moving.
After this is off, lift the pump housing out of the tank.
-Now to swap over the pumps.
Disconnect power wires and fuel line to pump.
Unscrew pump mounting bracket, and install new pump in it's place.
Do all the above in reverse to re install.
When it's time to start the car, click the ignition ON and OFF 2 or 3 times befor starting so that the pump can build up pressure.
CAUTION: Slippery When BOOSTING!