A 1934 $500 bill can be worth anywhere from face value up to $1,800 or more, while a rarer 1928 bill could be worth upwards of $16,000 in pristine condition. Special markings, condition and serial numbers all affect the value of the bill.
High-denomination notes such as a 1934 $500 bill were not typically used during their circulation. The lack of usage resulted in a large number of bills in excellent condition. Since these bills are usually in good condition, any weathering or damage done to these bills can cause significant reduction of value.
If they have a star marking near the serial number, 1934 $500 bills typically hold a much higher value than a standard note. This marking can increase the value to $1,800 or more. Bills with low serial numbers can also have increased value, especially if the serial number is two digits or less.