There is SO much free clip art on the web - especially good for holiday use! I downloaded a nice smiling pumpkin for my door from Avery.com - (and when it wasn't as orange as I would have liked - I colored it in with an orange marker and it's very nice on my front door, thank you.)
Here's another place that has a lot of free pictures to use. There are vintage Thanksgiving, Christmas, New Year's, Easter, and Valentine's Day postcards and lots of other great images, too. All free! They're at http://karenswhimsy.com/public-domain-images/ .