It looks like Amazon is no longer selling gift of prime memberships. The old link (our affiliate link) now leads to an error page. Previously it was possible to purchase these gift of prime memberships to lock in the membership price and then if you didn’t want to redeem them for membership they could be converted to Amazon credit instead by cancelling.
Amazon last put up membership prices in February 2022, before that prices were increased in May 2018. It’s possible this indicates Amazon plans to put prices up again in the near future, or Amazon might have decided to simply stop selling these memberships.