Looks real to me. I don't have my colonial book with me, so I can't tell you if its a contemporary counterfeit or not, but it's showing the signs of a proper note.
The different inks, red and black printing press inks, and the signature inks are usually a great way to tell, If they are all monochrome, then it's probably a fake.
The paper should be rather thick as it looks it is. The fold and it's wear and dirt also show it to be a good note. Also, the paper pulls on the back from being mounted in a scrap book (like stamps were done) are another indication that it is real.
Counterfeit notes are often printed in monochrome, and on paper that is like an old paper bag, sometimes it is shiny, too. I bought some facsimiles from a shop in Boston years ago and they are thin, but rather crisp paper.
As for value, get a consensus from
ebay sold items and Heritage Auctions sold items as well. If you can find it on Denly's of Boston, that's a decent price on the high side.
Great piece of history!