After-market vs primary registration
Primary = registering an unregistered domain at retail rates ($8-$60). After-market = buying a previously-registered domain from its current owner, usually at a markup.
Why prices differ
Primary registration is whatever the registry+registrar charges (often <$20/year for gTLDs). After-market reflects scarcity + bidding tension — premium .com names trade for thousands to millions.
Where each happens
Registrars (GoDaddy, Cloudflare, Porkbun) handle primary. Marketplaces (Sedo, Afternic, Deepnom) handle after-market.