I would say that the perk is you are a DVC member giving you the option to purchase membership extras. I stand firm a perk is something you get free. A paid extra is not a perk. Its a paid option. Never have I thought paying for anything was a perk. If it was a membership perk it would be included with the purchase of DVC direct or resale.
I own at Baylake Tower resale. One of the perks I use to have was being able to go up to the TOTWL and watch fireworks. Nevermore. I am forbidden. Maybe one day I can pay to go the top floor but, it wouldn't be a perk. It would be more like a reservation,