Right now Porkbun has the cheapest first year at $8.75, and NameSilo the cheapest renewal at $11.99. Over three years the lowest total at one registrar is $34.49 at Porkbun.
Why does .dev cost more after the first year?
Many registrars sell the first year below cost and recover it at renewal: at Porkbun, .dev renews at $12.87 after a $8.75 first year. Compare the renewal and 3-year columns before you buy.