Charleston [1]’s least-expensive lodging is also its most unique, the 
Not So Hostel (156 Spring St., 843/722-8383, www.notsohostel.com [2], $21 dorm, $60 private). The already-reasonable prices also include a great make-your-own breakfast, off-street parking, bikes, high-speed Internet access in the common room, and even an airport/train/bus shuttle. The inn actually comprises three 1840s Charleston [1] single houses, all with the obligatory piazzas to catch the breeze. (However, unlike some hostels, there’s air-conditioning in all the rooms.)
Because the free bike usage makes up for its off-the-beaten-path location, a stay at the Not So Hostel is a fantastic way to enjoy the Holy City on a budget, while having a great time with some cool people to boot.
Links:
[1] http://www.moon.com/destinations/charleston-savannah/charleston
[2] http://www.notsohostel.com