Bank robbing would be a piece of cake. Put everyone in the bank to sleep from outside, hex the cameras, walk in, empty the drawers, walk out. Several thousand dollars for a few minutes of work. Hell, maybe you could even do a portal cut by opening a Way into the Nevernever that bisects the vault door, cutting it open with a rip in space. Rinse and repeat across the country; with access to the Nevernever, you could hit anywhere you wanted with ease.
I know Harry frequently says that a lot of practitioners use their talents to make a lot of money, but I don't know how they do that legitimately outside consulting for people who already know about magic.