Albert Barnes Commentary 1 Kings 13:33

"After this thing Jeroboam returned not from his evil way, but made again from among all the people priests of the high places: whosoever would, he consecrated him, that there might be priests of the high places." — 1 Kings 13:33 (ASV)

Whosoever would, he consecrated him—that is, he exercised no discretion, but allowed anyone to become a priest, without regard to birth, character, or social position.

We may suspect from this that the office was not greatly sought, since no civil governor who cared to establish a priesthood would wish to degrade it in public estimation. Jeroboam did, however, impose one limitation that would have excluded the very poorest class. The candidate for consecration was obliged to make an offering consisting of one young bullock and seven rams (2 Chronicles 13:9).