Ibn Ezra on Leviticus 27:23

מכסת. כמו מכסת נפשות: THY VALUATION. Mikhsat (the worth of) is similar to mikhsat (number of) in according to the number of (Ex. 12:4).⁷⁶See I.E. on Ex. 12:4 (Vol. 2, p. 219): “Mikhsat means a portion.” That is, according to the portions which each one will eat of the Passover lamb. I.E. renders our verse, the portion (i.e., the number of years left until the Jubilee) of your valuation.