I prefer buying Prepaid because #1 Cost (i.e bought a Mobicel Rebel, installed custom ROM, without bloat and only apps I use installed for under R400), #2 I have more control of my data/airtime used without any adware.
Overall, was negating the feeling of throwing money down the drain!
Prepaid for me too. I normally buy a new year or 2 old phone cash (when the S10 comes out, Ill buy a S9 or a S8). Great savings, and the phones are still pretty much top of the line, minus a few gimmicks.