Check out SOLD auctions (under advanced) on eBay. That will give you a general idea. But there are rare some block runs (letters before and after the serial number) that demand a premium.
To currency collectors, condition is EVERTHING, so maybe some photos of what you've got would bring better answers. Welcome to CT BTW.
Usually they are worth One Dollar but it all depends on many other factors. Age, condition, run size, and the serial number and/or signatures all contribute to its value. Don't forget supply and demand.
Welcome to CT. Star notes can be found in circulation, for face value. Uncirculated examples start at just over face value and can run hundreds to thousands of dollars depending on many variables, like series, denomination, serial number, condition and availability. Clay Irving has an interesting article on his website, here -http://www.panix.com/~clay/currency/star.html
I keep any and all "star" notes of any donation that I come across. Just think what is the survival rate of any series? I know there are many so-called collectors that have people on the inside of banks that can get most of them today. These people are not real collectors. They are destroying the hobbies. Just think of "Stamps"? Today how many young coin collectors do we have. How many of the young can afford to collect any currency? I started with "Cents", because that all I could afford then at the age of 10 in the late 1940s.
That's true for the current series. But much later you will then and find out you let some go for the face, that now cost much more later. You can always let them go later to a very young starting collector to keep our hobby going. Each to his on.