Hey,
check out my post right here: http://roommates.heelshousing.com/topic/summer-2012-sublet I have a bedroom in a 3bedroom apartment that I need to sublease this summer so this works perfectly. The rent is 375/month with cable and internet included, and the only things not included are water, gas, and electric, which come out to be around 50 (no more than 70) per month, so you would be well under your budget. The A bus is right outside, and it is a short 10-15 walk to campus (it is behind North St (the street behind Rosemary).
Contact my roommate, Michelle Pujals, who can give you further details. Her number is 9194148022 and email is pujals@email.unc.edu if you have any questions about the place. Its located at 425 Hillsborough St and I can send pics or any other information.
Rita