One-time purchase
You buy DeskDrawer once. There is no recurring charge, no expiry, no trial that lapses into a locked state, no "pro" tier and no in-app purchase. Updates arrive through the Microsoft Store.
Because the Store handles the purchase, it also handles the licence: your entitlement is tied to your Microsoft account, so reinstalling or moving to a new PC means signing in and installing again, not buying again.
The price is set on the Store listing and varies by market, which is why no price appears on this site — see Licensing. A site that quotes a figure it cannot keep current is worse than one that points at the authoritative source.