Yes tricking people into paying the full price several times by abusing the itch.io system is clearly intended. This type of fraudulent pricing is even mentioned on https://itch.io/docs/creators/pricing as not recommended.
Viewing post in Knightly Passions [1.21 version] 18+ comments
Oh, so then it was deliberate. Very dishonest.
What's funny is that, since it isn't mentioned above in the description, it's fraud. It's a known problem, and the explanation is somewhere buried in the comments, but that doesn't suddenly make it legal to not disclose that you lose your access to your purchase should the price go up.