I haven't played in years, but I remember the 500 CSC gift card and the 1 month GA were top selling. Now I'm not sure anymore. There are so many items I can choose from. But is it typical to have 40m on hand to buy these?

CSC cards.

Yes, it's typical to have 35M on hand - quests easily give 3-5M a day, now.

Well, I got a lot of catching up to do. I spent 47m on that stupid Lemon Leaf Mouse and two Glade potions a few years back. Inflation is nuts over here.

I think GAs are slightly cheaper now thanks to the buddy account feature, which allows GA subscribers to gift a 1 month GA to someone.

Buddy GAs stack, so if you have generous friends you could go without buying a GA for a few months. That in turn means a bit less demand for GAs.

I'm always buying CSC gift cards so I think they're a good bet. :)