The relative values of the persons appear to be regulated according to an estimate of the probable value of their future work:
Ages Male Female From a month to five years of age 5 shekels 3 shekels From five years to twenty of age 20 shekels 10 shekels From forty years to sixty of age 50 shekels 30 shekels Sixty years of age and older: 15 shekels 10 shekels
As regards the shekel of the sanctuary, see Exodus 38:24 note.

And if it be a female - The woman, at the same age, vowed unto the Lord, might be redeemed for thirty shekels, 4. 10s. sterling, a little more than one half of the value of the man; for this obvious reason, that a woman, if employed, could not be of so much use in the service of the sanctuary as the man, and was therefore of much less value.

And if it be a female,.... That is, of the same age, full twenty years of age, and not more than sixty:
then thy estimation shall be thirty shekels; about three pounds ten shillings of our money, the price of a servant, Exodus 21:32; the reason of this difference of estimation between a man and a woman is, because the woman is the weaker vessel, and her labour and service of less importance and worth, such as spinning, washing, &c.

Thirty shekels - Less than the man's price, because she is inferior to him both in strength and serviceableness.