Hello,,don't tell me you are referring to Apple's website to compare the price?   It's up to the seller to decide how much is their profit margin depending on the quantity of supply ability. There are many websites offering competitive pricing too, some are too low and some are ridiculously high. If a seller sell it expensive, buyer pay more, VISE VERSA. Of course, every sellers knows best every Bolts and Nuts of the whole pricing before deciding to release their item. For some sellers are profit oriented while some others are customer service oriented. If you sell product A at RM10, doesn't mean other seller must sell it at RM10 too. (Now please don't tell me you family sell Apple products)

And regarding the eBay & Amazon affiliate program,  program organized by Amazon and eBay where 3rd party merchants will benefit 3%-26% commission from advertising products sold by the sellers. Instead of selling it, we actually buy the products from overseas and repack the item for local market. For sure, you are all in the eye of retail-ends. (You probably buy product at high retail price and never heard of bulk purchase commission)