Halloween anyone?

I know it is over a month away, but I am wondering, are any of you dressing up? And if so, what are you dressing up as?
I ask because this year I am dressing up. I haven't dressed up for Halloween in over a decade. Wait, scratch that. When I taught preschool a few years back I guess I did dress up for our Harvest Parties. But that's it. The last several years have involved me sitting at the house with a giant bowl of candy, and like 5 trick-or-treaters. So I end up eating wayyyy too many fun size Snicker's bars. *Note to self- by Mounds or something else nasty this year.*
Why is this year any different? It's my sister in law's birthday. Well, I mean, it's her birthday EVERY Halloween, as she was born on October 31st, but this year she and her husband (Dave's brother) and a bunch of their friends are coming up to Portland to...."go out on the town". And apparently everyone is coming in costume.
I am having a really hard time finding something!! First of all, I refuse to spend more than about $20. Because, I mean come on, it's a costume people. It will be worn once. Even I can't justify that splurge and I am the queen of justifying $20 splurges (Hello Old Navy clearance!!). Also, I am having a hard time finding something age appropriate. I am approaching 30. Yes, I am currently only 27, but my Jessica Simpson math tells me 30 is right around the corner. Can someone who is almost 30 really go out as Raggedy Ann?? But at the same time, I would like something semi-respectable. I do not want to look like I am headed to the Halloween party at the playboy mansion. Not only for modesty issues, but it's OCTOBER. In OREGON. Seriously. Some of these costumes are so skimpy with so little fabric...I would freeze! Not to mention get arrested for public indecency. And why spend money on something if it is just going to be covered up with my big wool coat?
Hmmm.... to be continued...