Pick a volume, pay once, and the gigabytes land in your reseller pool immediately. From there you mint prepaid activation codes in any size and sell them at whatever price you like. Nothing expires.
The rate is set by the rung you reach, and it applies to the whole order. Minimum 500 GB; above 2 TB the price is agreed directly.
Priced by the server, not by this page.
One payment, no monthly fee, no contract. Crypto is credited as soon as the network confirms it — usually a couple of minutes. An account is required, since the pool has to belong to somebody.