Just to comment on crew uniforms for a moment here. US Airways in particular wouldnt have a leg to stand on in accusing someone of breaching security when selling one.
US, in thier ongoing effort to be the worst looking airline in the world, has a generic uniform for all employees. You can order a complete US pilots uniform from CrewGear. You can order the "everyone else" uniform from Cintas... its an early 80s poorly made cheap navy suit! Not exactly exclusive or difficult to recreate.
You dont see many US Airways uniform items on ebay because they dont look like flight crew uniforms. Imagine your kid wanting to be a flight attendant for Halloween and getting them the US uniform. They'd be so disappointed. "Trick or treat!" "Oh hello dear, what are you dressed as? An insurance salesman? Oh, I know, a funeral home director- spooky!!!"
I remember hearing of a F/A that went out on Halloween in her mothers old PSA uniform and was quite a hit.