Many registrars offer steep first-year discounts but charge significantly more at renewal. The 5-Year Cost helps you see the true long-term cost of a domain:
5-Year Cost = Registration Price + (Renewal Price × 4)
For example, a registrar offering .io at $19.88/yr registration but $39.88/yr renewal has a 5-year cost of $179.40 — while one offering $29.00/yr for both registration and renewal costs only $145.00 over 5 years.
Always compare renewal prices, not just registration prices, when choosing a registrar.