Most Junkyards or scrap metal yards that buy Junk or scrap cars pay by the ton or lb for the car.
So the amount the Junkyard or scrap metal yard will pay for scrap cars depends on the weight of the car.
Some scrap yards pay $50.00 per ton for scrap cars while others may pay $150.00 per ton for scrap cars and sometimes less and sometimes more depending on the per ton price of scrap metal at the time.
Scrap metal prices can change daily so it's best to call the scrap yard and see what they are giving for scrap cars at that time.
The last time I took a scrap car into the scrap yard I got paid $150.00 for the car which was not great but not too bad either.