[philadelphia] Is 45% a normal contingency fee?

So my fiancé and I are exploring our options and had a consult with a real estate attorney in Philadelphia. He said that his firm charges 45% contingency and if we don't win, they eat all the costs.

Is this normal? What are the pros/cons to using a contingency fee?

If you look at my post history, you can see what the case entail (if you'd like to know).