2000 Buick Century 2000 Buick Century Window Regulator

My windows won't go up! When the button is pressed to activate the automatic windows I can hear the motor working but the window doesn't move. The windows will go down however. I called a mechanic to see how much it would be to replace these window regulators. I was told that the regulators come with a motor and that the total for 2 front window and 1 rear would be $900! Is there anyway to fix this on my own or do I have to suck it up and pay almost $1000 dollars to fix three windows.