Luckyrollers:
Your star notes were issued by the Federal Reserve Bank of New York as you can see in the seal on the left side. They are 1969 Series C notes. There were only 256,000 of these particular notes printed. In my book, which is a couple of years old, the value ranges from $135 in VF-20, to $160 in EF-40, to $400 in Unc-63.
Those values are, of course, retail, so a dealer would have offered maybe 60% of those figures in 2005.
Your dealer, telling you there isn't much market for $100 star notes in general may be telling the truth. Remember, the buyer/collector will first have to pay the face value of the bill, then pay the premium for its rarity. I would have to imagine there are more buyers for a $1, $5, $10 or even $20 than for a C-note. You may have good luck selling them at a larger coin show, or on
ebay or another auction site.
Good luck.