Hilton hotels generally have 2 levels of wifi. Low speed is free to guests and high speed is paid (unless you are a Hilton Honors guest) The lobby has free wifi too in most Hilton hotels I can't remember their specifics
You can get local sim cards which decreases costs enormously
I just noticed on the bus tour letter that was sent a little while back, the buses are debating from the Elangeni Hotel. I seem to recall in the past 2 years they departed the Hilton Hotel. Anyone know why the change?