I believe that the above is one of the frequencies used by Cell C (from frequencycheck.com)
If I buy a phone that does not support this frequency, does it matter?
Below are the bands that the phone does support.

GSM
Compatibility - 2 out of 2 bands supported
100%
Interface Name Supported by device?
GSM 900 (E-GSM) Yes
GSM 1800 (DCS) Yes

UMTS
Compatibility - 1 out of 2 bands supported
50%
Interface Name Supported by device?
UMTS B1 (2100) Yes
UMTS B8 (900 GSM) No

LTE
Compatibility - 1 out of 1 band supported
100%
Interface Name Supported by device?
LTE B1 (2100) Yes