10,000*.30= 3,000
10,000+ 3000 = 13000 is how much the salesperson soled it for.
13,000-1,000= 3,000 (the difference)
3,000*.25 = 750 it 25% of the difference of the auction price and the dealership price.
So the commission that the sales person received was worth $750 I think thats correct.