I would say let it go unless you can really afford to hold it. $100 is a lot of money to let sit on a newer circulated note. The radar serial is neat, but for me not neat enough to keep $100. If it was a $1 in any condition...sure, but not a $100. I don't think it is really worth much over face because it would be really hard to find a buyer. It may "technically" have a value above face, but it would be really hard to get it.
Spend it. Even in excellent condition it's a tough sell. Stained and creased through the portrait = $100
Alas this forum has lately devolved to 45% zombie threads, 50% "Is this beat up bill with a mildly uninteresting serial number worth keeping", and 5% new stuff people get. That's a tough signal to noise ratio there...