Window Problem

I have a 2001 Mitsubishi Galant. About two months ago, I heard something fall inside the driver's side door when I closed it. It just sounded like something little, but once this happened, I could not open the window anymore. When I push the button to open or close the window, it makes the sound like it is trying, but nothing happens. Furthermore, since then, the window has been slowly drifting down. It is now about 2 inches down from being closed. I tried to ignore it for a while by putting a bag over the window on rainy days, but I really need to address this. I am not a car pro, but I am gleaning from phone conversations with Midas, AAA and other local repair shops that it is the window regulator or motor or both, but they cannot tell me unless I bring the car in and pay between $60 and $80 just to have them take the panel off the door to determine the problem. They cannot even give me a ballpark idea of how much a regulator and/or motor would cost if that is what is needed. I don't want to pay $80 only to find out it will cost $500 to repair it, which I cannot afford. Furthermore, I am a distrustful person who believes that, unless I know and can see exactly what the problem is, I believe a car repair shop will say it is something worse than it really is just to make a buck. I am going to take the door panel off myself and see what I see, but based on the information I have provided, what does it sound like? Something inside the door fell, the motor sounds like it still works, and the window has gradually drifted downward about 2 inches over the course of the past 2 months. Thanks!