I'm not sure why they do this, but they'll price match if you show them Apple's price on your phone.
Best Buy does this with nearly all of their products. I bought a Razer mouse from them the other week that was $67 instore and $50 online, on their own website. Memory cards are equally as gouged - I believe their standard practice is to take advantage of non-savvy consumers. Thankfully they price match, it's just a hassle and a bad experience because if you buy more than a couple things, they stop letting you price match on the same order.
I've also run into issues where Best Buy seems to have their own unique model number for certain Sandisk memory products that differs by one number or letter (but is the same exact product sold elsewhere), so they refuse the price match. This is some truly underhanded stuff that mattress/sleep product stores used to partake in, but I haven't been able to confirm this multiple times as I usually just stick to Amazon unless there's a local emergency.