First you have to find out if it's real. A lot of early currency has been widely copied and counterfeited. The only way to tell is to have the bill inspected in person by a paper money expert such as a dealer or appraiser.
On Pawn Stars
Ebay auction
A dollar. They're not rare.
They sell on eBay for around $8.
500 $ worth
Ebay, local coin shop, online dealer
These generally sell in the $200 to $300 range.
These are very common among collectors and sell for about $1.25
No. He didn't sell it. He let the cashier hold it, in exchange for the 100 dollar bill. That way she could trust that if he ran off with the money, she would have the watch, which costed about the same amount.
6-15 depending on the buyer if your looking to sell it
Five Dollar Bills from 1934 appear to sell at about $30.
These are common in collections and sell for face value only.