down payment and seller financing

[Keith Faris]

Lets say I buy a house for $300k from a seller with seller financing. I give him nothing down. Then I find a buyer who will buy the house for $330k with $50k down. Since I've collected $50k, I will be financing the remaining $280k. But,since I owe the original seller $300k, if we were to do a simultaneous closing, won't I have to show up with the $20k difference? Thanks!