If it is appropriate for you to wear a suit for an occasion (outside of church, weddings, and funerals), then you are likely making enough from the position to pay for the suit.

This doesn't apply to me, but couldn't this be a catch-22? To get a job/social status where you're making good money, you need to get a suit, but you need the money for a suit in order to get that job.

Also, you could just be averse to a perceived waste of money, even if you could afford it (my case).

It isn't a catch-22 so much- you don't need to be making banker money to dress like a banker, so you can climb the ladder over time.