Law firm ads all look the same because they're all made the same way: a stock photo, a headline about fighting for you, and a form. They're expensive because every firm in your market is bidding on the same keywords with the same creative, and none of it gives a prospect a reason to pick one over another.
You have something your competitors don't: an hour a month of yourself talking. A thirty-second clip of you explaining what actually happens in the first month of a case will outperform a stock image, because a prospect can see who they'd be hiring before they call.