There are 20+ major universities in South Africa (depending on who you count and who you don't) and each of them has some kind of DL programming on offer. Clearly, UNISA is the DL leader but if you dig around a bit you'll find some golden nuggets. South African schools may have some shortcomings but, in my own opinion, if money is a critical issue for you (as it is for me), then you should at least be aware of what's available in these schools. https://en.wikipedia.org/wiki/List_of_universities_in_South_Africa
I've been considering a doctoral program in SA for a while now but aside from SATS, the websites are really difficult to navigate.
I wouldn't consider the SA schools unless you already have your doctoral research underway and have a very good idea what you want to do; the low cost reflects theeducational product which is the bare minimum.