lol, this sounds so ridiculous. Have to fight a store to do something that they are supposed to do according to the company's policy. lol
I'm somewhat familiar with retail stores and their agreements with manufacturers.
While price matching is now more common as a result of policy changes, they still have to abide by their resale agreements with the specific manufacturers. Different agreements allows the manufacturers to dictate the the lowest sale price of their items sold at Best Buy and when those sales occur. If those prices are violated, then companies like Apple can revoke their agreement and pull their items off of Best Buy's shelves. I should note that agreements are different between authorized Apple resellers like cell phone carriers, Target, Best Buy, etc.
In this instance, Apple's agreement with Best Buy is more than likely more stringent than it is with other stores. An example of this was last summer, Target was selling iPad 3's at $20-50 off (I forget the exact sale). While some customers came in wanting to price match, if an employee went through the POS system to reduce the price, that sale would be FLAGGED as a type of breach of said agreement. Granted, it could've been done with manager approval, but there's no telling when a manufacturer will say enough is enough.
Also, you'll notice that only SOME Best Buys are authorized Apple computer retailers. If you go to one that is NOT an authorized Apple retailer and an employee sells you an iMac for in-store pick-up at a Best Buy store that is, that is a HUGE no-no and can be reason for Apple to cease their agreement with the Best Buy's in that region or district.
Another example is Costco. A few years ago, Costco was allowed to sell some Apple products like iTunes gift cards and iPods. However, their agreement with Apple was that they were not allowed to sell iTunes gift cards online. Furthermore, Costco was not allowed to sell iTunes gift cards at some of the discount prices they were actually selling them at. This ended up leading to a mutual falling out between the two companies.