Back when I got married in '64, I signed on with a computer manufacturer (since defunct) for the grand salary of $6000/year. And was considered upper middle class. I have worked with computers, with the Space Shuttle, with the military, and even owned a retail store. All that time my income, and the cost of goods, increased. I estimate about 1500% more or less.
I have a question: when is the last time you adjusted the dollar cost of items in the store for inflation? Or the cost of a subscription?
Netflix has about a zillion more subscribers than you, gone up 20% or so in the last few years.
Amazon, with profits in the billions, DOUBLED the price of Prime two years ago. Lost maybe .ooo5% of their customers.
You need to adjust to the reality of inflation.
My suggestion: Keep the VIP at about $10-12/month, and increase the cost of DDO points 25%, no sales. Increase the price of AS, XP boosts, and tomes 50%.
Oh, and make the Hardcore permanent, with rewards for reaching levels 20 and 30 only.
I'll still play, for a few more years at least.
The Grand Old Man of Cannith