Domains do not cost $0.18 to a registrar. ICANN charges registrars a $0.18 ICANN fee and then the company that owns the TLD (the registry) charges whatever they want per domain. Then your registrar adds their markup to the ICANN + Registry fees. Currently, a .com costs $7.85 + $0.18 + Registrar Markup. (I run a domain registrar)