Right now internet.bs has the cheapest first year at $29.99, and Instra the cheapest renewal at $0.49. Over three years the lowest total at one registrar is $149.64 at Sav.
Why does .fo cost more after the first year?
Many registrars sell the first year below cost and recover it at renewal: at internet.bs, .fo renews at $60.90 after a $29.99 first year. Compare the renewal and 3-year columns before you buy.