Great way to do it is to look for sales - Fabric Depot normally has sales once a month on specific pattern makers (all Butterick or all Simplicity, etc) and you can pick them up for $1.99 - Since it's halloween - time, you can also try over at Jo Ann's to see what they have on sale. They sometimes have Simplicity costumes on sale for $2 per pattern...

You can also try going to local yard sales in the area that specifically state they're selling sewing items. A lot of times, you'll find patterns available there, too...

Good luck!

~M