The rear end is broken. How much to repair it? the brakes froze at the same time on 1994 Ford Aerostar

AS the rear end started making noise, the brakes started to freeze up and then release. How much to fix this?

Asked by for the 1994 Ford Aerostar
Either the brakes are locked up or the rear differential is but not both at the same time!!
Sometimes the brakes freeze. This didn't happen at first. The rear end makes a terrible noise. Esp. when I go over a bridge. Something is dragging. When I took it in, they just the rear end is busted.