In my opinion, I'd bet the guy bought a stock Bronco for three or four thousand dollars, put on a lift kit, installed new seats, bought new tires, and is trying to turn around and sell it for a profit.
None of the rust has been addressed, he gives only vague comments about the rust but builds up the new seats and lift kit like they are the biggest selling points.
I'd be real concerned about those rocker covers. Odds are the original rockers are rusted out or otherwise damaged. Especially with the rust issues he actually shows in the front door post.
I'd be hesitant to buy it because he doesn't give accurate enough descriptions of the rust issues or anything else he may have discovered.