Charleston SC Income Investment Properties | Multi-family Real Estate for sale Charleston SC Area. Many real estate investors like the income stream, and investment potential that only owning multifamily properties can bring, and Charleston SC is no different. Charleston SC real estate market is very robust as a standard and the rental market does very well considering that Charleston has the highest standard cost of living in the entire state. Homes around the College of Charleston, and the Medical University of S.C do very well from a rent perspective as housing is scarce so rental income per unit is high for the area. Apartments for sale in Charleston SC and cap rates vary depending on area, age of property, type, and size of the property as one would imagine. Duplexes, tri-plexes, quad-plexes and apartments go up for sale regularly throughout the year in the tri-county area.