If anyone making the vow is too poor to pay the specified amount, the person being dedicated is to be presented to the priest, who will set the value according to what the one making the vow can afford.
NIV
But if the man is too poor to pay your valuation, then he shall be set before the priest, and the priest shall value him; according to the ability of him who vowed shall the priest value him.
AMP
But if he be poorer than thy estimation, then he shall present himself before the priest, and the priest shall value him; according to his ability that vowed shall the priest value him.
KJV
"And the land of Egypt is before you; settle your father and your brothers in the best part of the land. Let them live in Goshen. And if you know of any among them with special ability, put them in charge of my own livestock."
NIV
The land of Egypt is before you; make your father and your brothers dwell in the best of the land. Let them live in the land of Goshen. And if you know of any men of ability among them, put them in charge of my cattle.
AMP
The land of Egypt is before thee; in the best of the land make thy father and brethren to dwell; in the land of Goshen let them dwell: and if thou knowest any men of activity among them, then make them rulers over my cattle.
KJV