Abs Light Stays On

Does anyone have a problem with the ABS light staying on and not going off? I took the van to a mechanic and he said that I need a $1200.00 Module. Is this guy just trying to make a buck or can I check other things. I know the rotors and brakes are good and full of fluid. Just needing some information.

It could be the module, but it most likely is a wheel speed sensor or even, but less likely, an exciter ring. I would definitely get a second opinion before getting it fixed. At least have it scanned by another mechanic and see what they say.