What’s the best deal you’ve gotten on cars or parts

1970 Duster got it from Carmax 6 years ago, 318 with edelbrock heads air gap intake 750 carb, 8.75 rear end with 3.91 sure grip, drove it home, trans was not the best, did not make any improvements to engine, when i pull it, the car was running 11.70s. I paid $2800 for it