At least in Tshwane, it is illegal to profit from electricity sales in an estate. I think it is also a NERSA regulation. Your estate should only be allowed to charge the NERSA approved tariffs for electricity.
Our estate used to charge their own tariff and buy in bulk. Tshwane told them to stop that immediately or face legal action. We now pay Tshwane prepaid tariffs.
The estate was using the profits from electricity sales to subsidize other budget items. I pointed out that all estate costs must be recovered from the levy, otherwise high electricity users are subsidizing low electricity users for the estate costs. The levy must cover all budget items fairly and equitably. Our managing agent is also Trafalgar, so they know about this, but hey, property management companies aren't the most honest bunch around.