John Gill Commentary 1 Kings 10:29

"And a chariot came up and went out of Egypt for six hundred [shekels] of silver, and a horse for a hundred and fifty; and so for all the kings of the Hittites, and for the kings of Syria, did they bring them out by their means." — 1 Kings 10:29 (ASV)

And a chariot came up and went out of Egypt for six hundred
shekels of silver
Which, reckoning at two shillings and six pence a shekel, amounted to seventy five pounds; but a shekel was not worth more than two shillings and four pence farthing:

and an horse for one hundred and fifty ;
and this being the fourth part of the above sum, the Jews gather from hence that there were four horses in a chariot; the horses must be reckoned one with another, the whole collection of them, or otherwise no doubt but one horse was better than another; and it was a pretty large price to give for a horse in those times; which, taking a shekel at the lowest rate, must be upwards of ten pounds; and which is too great a sum still for a custom or tribute to be paid for them, whether to Pharaoh or Solomon, as some understand it:

and so for all the kings of the Hittites ;
perhaps the same with the kings of Arabia, (1 Kings 10:15) and for the kings of Syria; those of Damascus, Zobah

did they bring them out by their means ;
that is, by the means of Solomon's merchants, who bought them out of Egypt, and sold them to these kings.