What is the value of a US 2 dollar bill with a star?

The value of a star note is usually somewhat higher than that of a "regular" bill, but the extra value depends very much on the bill's date and condition.

If it's a modern (1976 or later) $2 bill, regular-issue ones are only worth face value so a circulated star (replacement) note will only be worth 50¢ to a dollar more. A nice uncirculated one could bring around $4.

If the bill is older please post a new question with its date and what letter if any is after the date. You don't need to copy the entire serial number.