We just came back from Charleston visiting DS. Loved the city - it is either GORGEOUS or the houses are falling down. Didn't seem to be a middle ground.
Good luck finding a hotel in the historic area for 100. We sure couldn't - but it was a football weekend for the Citadel and a Cruise weekend (saw the ship docked) so maybe you can find one. We stayed in the Hawthorne Suites out on Rt 17. It wasn't a bad drive in. There are lots of hotels along this road that looked good..Best Western, Holiday Inn, Comfort Suites to name a few.
We used a restaurant.com GC for Toast on Meeting St. The restaurant is attached to the Days Inn downtown, but the food was very good and moderately priced. In fact, we also ate at the famous Hymans and I liked the food at Toast better! Go figure.
There was a cool Farmer's Market beside the Old Citadel on Saturday. A vendor was making fresh donuts!
We checked out the Market and did some shopping, - also tons of shops up and down Meeting , King and side streets with a restaurant on every corner.
We walked along a waterfront park with gorgeous fountains and just kept walking east along the river. We passed "Rainbow Row", beautifully colored row houses and ended up at the Battery. It was a great walk and gave us time to absorb the atmosphere and appreciate the superb architecture.
Also wanted to mention that The Citadel has a cadet parade every Friday for free and their museum is free also.