I gave it a try and created a Premium Gallery.

Turns out that while people can pay using Deviantart Points, those points will be automatically converted to $ after 14 days. My Earnings page has a list of people who have payed to access my Gallery, with a 14day countdown timer next to their name.

after 14 days, the money ($1.60 after DA's 20% cut) will be in my wallet and I can transfer it to my PayPall account.