Putting my numismatics hat on

The three factors in collecting are condition, rarity, and demand. Oh, and things that look pretty.
If the piece/note is quite rare then the condition doesn't matter that much.
If the piece is fairly common then it needs to be in immaculate condition to demand a good price. You say your notes are folded - that will definitely drive down the price, unless there's something special about them, eg they are a reissue of a destroyed note or have an unusual signature on them. That's probably something that a scrupulous dealer would be able to tell you.
And if there's more buyers than sellers then all the better for you
In any case you need to show them to a dealer. Just be aware that dealers do it for a business, and will add/remove their margin from any supposed "book" price...
The other option is that you put them in an envelope and sit on them for another 10 years. The prices only go up.