An overview of the general cost of living index for Rapid City, SD is displayed above for your reference. Residents in Rapid City, SD enjoy a cost of living index of 93. This index is 3% higher than the South Dakota average, and 7% lower than the national average. The following categories are used when determining the cost of living index for any given city: health care (5%), transportation (9%), utilities (10%), groceries (13%), housing (30%), and goods/services (33%). Clearly, housing and goods/services make up the majority of the formula for calculating the cost of living index. Because of this, the general cost of living for any given area can be estimated by looking at the cost of everyday goods in that area. For those living in Rapid City, SD, the average cost of goods and services is 3% lower than it is in South Dakota, and it is 8% lower than the national average.