ABS Module?

[bakhsh]

Sporadically, while driving, the ABS, BRAKE, and DSC lights will come on and stay on, and it feels like something is holding the car back and it cant accelerate properly. I took the x5 into the dealer today, and after $75, they told me that the vehicle needed a new ABS module and that it would cost about $1500. i was shocked because this just started happening and the vehicle drives fine except when these lights come on...they usually come on after ive been driving for about 5 minutes...any advice on whether this is the correct problem and if so, where can i buy one of these modules cheapest and get it done myself? Thanks so much for all your help!!!