It seems to me a bit different.
They offered initially $ 2,500.
Then he replied saying that the price was $50,000.
Then he rejected the offer of $ 50,000 and was offered first $ 100,000 and then (through a different agent) $ 200,000.
Of course IANAL (and know anyway very little of US Laws) but if this corporation really-really believed that the $50,000 reply actually amounted to a binding contract, they should have attempted to have it respected immediately, the two later offers, doubled each time, sound nothing like "good faith" (probably irrelevant in court, still ...).