If you are looking for something cheap to do the FIDM Museum is always free. Their current exhibition is the 6th Annual Outstanding Art of Television Costume Design. It celebrates the work of Emmy nominated costume designers by letting you see the costumes of over 70 television shows. Featured television shows include Boardwalk Empire, Downton Abbey, Game of Thrones, Once Upon a Time, Pan Am, Smash, Magic City and more. This exhibit is ending October 20th so you only have a few more weeks to go check it out.
The museum is open to the public Tuesday-Sunday from 10am- 5pm. You can get more information here.