Ok. For what it's worth, my rear wheel got stolen off my around town mountain bike a couple of years ago and all I could scavenge for replacement was a wheel with a 7 speed cassette. Other than the trouble of running that with a 8-speed indexed shifter I never found the range going from 24 to 21 to be limiting. Does depend on the terrain though.

For that price, if you ride the CSs and like them I wouldn't worry about it. After all, once you buy a bike you'll be in the rather precarious position of having only 1 bike. If the gearing proves to be limiting you'll know for your next one.