Unreasonable price hikes

There's something fishy with takealot prices, you see an item today on a certain price, minutes later the price goes up , or as soon as you place the item in the cart the price changes to a higher price. Eg energizer rechargeable lamp was R499 yesterday, this morning the price has gone up to R609 , I've been eyeing single burner butane gas stove for over 3 weeks now , it's price keeps escalating daily. If their sales are surging, why the need to hike prices???