Expensive chinese product sold for 300% more than market price

I recently purchased a Superfly , 8000mAh power bank from a Vodacom shop. The price was R799. If I just knew, the exact same product id costing R299 on Takealot, exact same model. I then did the same comparison with mobile covers for an I-phone 7, in some cases the price is 300% more expensive than buying online. I do understand that it might be more expensive due to overheads, but please, this is ridiculous.