A lot of these 'discounts' aren't even discounts...
Guys I work with have FNB and think they are getting cheaper flights, but a quick Skyscanner or Kayak search reveals the discounted price to be higher than the market price.
Same goes for discovery and pick n pay... They only offer the discount on the undiscounted/rip off fruit and veg (not the cheaper bulk or loose packs)...
So, no, I'm not saying shop at ShopRite, I'm saying before you pay yourself on the back for getting such a 'good deal' maybe check once or twice and realise you have probably been duped!