Low Volume Direct Mail Services?

Are there any direct mail services that let you send a newsletter to just 100 people or so? Most I have looked at have a minimum number of 1,000. I know there are services where you can send individual letters (like snailmailr.com etc) but they charge like over $1/letter. Ideally I want to be paying $0.50/letter or less for printing and mailing.

You may wish to use VistaPrint...

I have not actually used them before, so I cannot personally vouch if they can do what you are looking for, but I have heard that they do low volume stuff relatively cheaply (for postcards).