That cost comparison chart is total BS and misrepresents traditional terminals. If they get such basic info wrong (which can be obtained by anyone with a 5 min phonecall) I wouldn't trust anything else they say.
I've got (had) a Pebble (horrible, horrible device, one of my least favourite electronic devices ever) which has the R50 rent/3.75% pricing model. Just this week I converted over to a Capitec machine; 3.25% on credit cards, 1.75% debit cards, R399/mo for a mobile device (no extra costs, that includes the data from the built-in SIM and everything) ... R25k-R35k was the breakeven that I calculated (remember with the Pebble you still need a phone & data). And you won't have customers walking away from a sale because of the crappy POS terminal you pull out in front of thing - something that has happened a few times.