My wife uses the email marketing program Emma, which she loves and is very effective for her purposes. The basic plan is $30 a month, which includes up to 1000 emails (1 email to 1000 customers, or 5 emails to 200 customers, etc.)
http://www.myemma.com
It's apparently gotta a higher degree of template design and customization than most, and has good reporting. Pretty easy to use, but I have no idea how it really compares with others out there.