I bought it for $ 9.99 on 17/04/2016 and I'm going to get the update, and it still asks me $ 4.99 for this update, c a DCL or a scam?
RC Quadcopter Racing Simulator · By
You shouldn't have to pay for it again.
You should just be able to download the latest version from your personal download page, without any extra cost. (Even though you bought it during the introductory sale).
Not sure if anyone else is experiencing this problem, you can try emailing support@itch and see if they have an explanation, they handle all the purchases/downloads.