Considering the retail price will be rising from 450,000 to 750,000 and they will be purchasing them at 250,000 a piece, they've just ensured their investment.
3 cars retailing at 750,000 a piece will go for 2,250,000$, the same amount they will have put in including the purchase of the cars, in addition to the interest on the 500,000$ loaned. Smart.