How much is a 10 dollar bill?

Answer 1

A ten Dollar bill is always worth $10 US Dollars, if American and genuine.

The bill is worth more to a bill/note collector. In this case the better the condition of the bill the better. Also the Series date is important and who signed it as the Secretary of the Treasury. All of these combined will value the bill more or less and the market is always changing.

Go on eBay and look at previous auctions for value of the bill.