First, paper money is not minted, nor is it a US Mint product. Paper money is printed by the US Bureau of Engraving and Printing. Second, I may be wrong, but I don't believe your note came off the presses like that. It looks like it was tampered with.
It looks legit to me. You can see that about halfway across the bill the ink starts to slowly and gradually fade and then it fades completely. That would be consistent with an inking error rather than someone applying acetone to remove the ink. That's just my opinion though.
It seems like the pricing on insufficient inking is all over the place. Being that your note is circulated, and the lack of reverse inking is pretty major, my best guess would be $60-70.
