Hi Klahanie,
When you do offer to sell your notes to a coin dealer, don't expect to dealer to offer you "full" catalogue prices. For example, if the $50 note that you have is in VG condition and valued at $90, I wouldn't be surprised if the the dealer offers $60. They have to resell the note and also make their profit to cover their expenses.
It's like the tv show Pawn Stars - some people think that if the item is worth $100, they'll get $100 from the dealer.