Paying poorly would bias you to candidates who will accept poor wages. Good candidates, even if they are young and inexperienced, can have a high market rate.
Percieved risk is higher for people with less industry experience. So if you believe, as I do, that people systematically overestimate the risk they take on bringing juniors on board, and hence systematically underhire them, then this would likely end up being good on net for juniors, as more of them would then be offered a chance to prove the bias wrong.