2002 Dodge Grand Caravan

I was driving along, and all the lights came on and the speedometer, and RPM thing went to zero. When i got home, i shut it off, called someone, they said to bring it there. then it wouldnt start. he has had me buy a brain, coil pack, crank shaft, now he wants me to buy a wire harness, can someone help me please, they are almost $500, im spending so much for no progress.