PlayStation’s Southeast Asia promotion runs September 17–30, with savings of up to 25% for new members buying a 12-month PlayStation Plus membership. The official announcement describes a separate upgrade offer for existing members moving to Extra or Deluxe, calculated on their remaining subscription period.
Joining and upgrading are different purchases
Do not assume the headline annual discount also applies to an upgrade. Compare the offer shown for your account with the remaining time on your current plan. A percentage alone does not establish the final local price.
Check the plan, not just the game list
PlayStation names the Game Catalog among the higher-tier benefits and specifically associates the Classics Catalog with Deluxe. Availability varies by plan, country and time. The announcement links to the service details and terms; it should not be read as a guarantee that every named title is available with every offer.
Consider the renewal as well as the discount
The announcement says the subscription renews automatically at the then-current store price until cancelled. Our practical takeaway is to compare three things before buying: the amount payable now, which benefits you will actually use, and the renewal commitment. A discount on a plan you would not otherwise use is not necessarily a saving.