OK. Well I was under the impression you were telling him to try and get a full refund by trying to pass it off as an unopened item because of this:
maybe you can package everything bak up , make it look unused, trim the wires and shit to look unused, and if they take it back, go to CC , buy the d3 and u get ur $100
And yeah, it would go right back on the shelf. I've known a few people who worked at a best Buy, and that's just what they do. If the item is unopened, they re-enter it in stock and put it back on the shelf. If it's opened, they inspect to see what's missing and all, repackage it, and sell it as a discounted open item.
But if you're only suggesting now he just take it back to return it as is he won't get a full refund, the honest way, he'd be charged a restocking fee, because the store wouldn't be able to sell the opened item at full price.
From Best Buy's website:
Restocking fee
A restocking fee of 15% will be charged on opened notebook computers, projectors, camcorders, digital cameras, radar detectors, GPS/navigation and in-car video systems unless defective or prohibited by law. A restocking fee of 25% will be charged on Special Order Products, including appliances unless defective or prohibited by law.
But the question there is, how much is that restocking fee? 15% of $699 is $104.85. Which would make returning it to buy it for $100 cheaper somewhere else a loss of $4.85 plus the time it takes to uninstall the first unit and install the second one.