We are still not able to provide precise estimation due to the lack of software testing in an adequate environment. Regardless, there are certain factors that affect the number of data transfers - number of active cameras, the average number of detections, the average number of streams, the average number of demanded recordings, remote access, stream quality, framerate, etc.
We tested one camera in a system that potentially has similar data traffic frequency as it could be the case in a betting shop. Based on this test examination, the traffic expectancy is somewhere between the 18 and 25 GB of traffic.