You only have to buy once.
Have you checked do you own any other itch account? That happens regularly.
I had to jump through a few hoops. I had to attempt to buy it again and then choose the link " Hey I already own this.." Then I had to request a download of all the games I have purchased and there it was.
Thanks
Ahh that's good to know, a bit frustrating but at least I can direct people to that link now. Thank you so much for the information!