(Going Green in 09) Quality Scanner Needed!!!

Hi All,
Could someone suggest a quality scanner to help us better organize the voluminous amounts of paper we collect through both work and home activities. My wife runs her own business in which she keeps numerous documents on file. I intend to use this scanner in her home office as a means to file all documents without all the paper. Ideal scanner is designed to quickly scan and archive documents in PDF. Photo quality of the scan is not a priority but it needs to keep the documents legible when reproduced and/or printed later. Office PC is currently running Vista. Thus can you please suggest a quality scanner (preferably USB) for this purpose, within a budget of $500 or lower. Thanks,

Plustek is best! They have so many! Even some that scan hard cards like ID's and credit cards. Check them out here: http://www.plustek.com/product/main.asp