It's mid-October, which in my childhood was the time Dad would take me down to the TG&Y to buy a cheap, vinyl Spider-Man costume with flammable plastic mask.
If the smell of polypropylene, and dyes that run off when you sweat on 'em make you nostalgic, Xbox Live Marketplace is selling avatar costumes. There are 16 costumes for 240 Microsoft points apiece, which translates to about $3, which is probably what skinflint Dad paid for those deathtraps Fletch and I wore.
Some getups, however, do not come with masks and or hats, which run another 80 points. The razor-blade apple and LSD-dipped tootsie pop are not available at this time.