Online and Instore Price Difference

I want to purchase the Springwood Wood Style Deck Box. The price advertised on your website is R1495. The price instore is R1710. To purchase online I have to register and give Builders my ID number and credit card/debit card details. I don't want to do this. I would prefer to purchase in store. According to the store manager if I want this item at R1495 ...I can purchase online and collect at the store. Why can I not simply purchase in store and get the item at R1495. Builders needs to rethink their strategy for online shopping.