Always haggle with the BB manager on open box Apple gear. I was told it costs them $400 per month per device to have old Apple inventory in their stores. This is a fee imposed by Apple themselves because they don't want old machines to be sold vs. newer ones (includes iPads, too) so BB is hugely motivated to move stock at negotiable rates as it costs them a fortune to keep old models/open box units in their cage.
Haggle, haggle haggle. Walk out with a screaming deal. Then, email Apple support and tell them the BB manager told you the machine has a full 12 month's worth of Applecare. That's how I got my reset, no issues (on an 11" MBA I've since sold - was an floor model and way used).
FYI, not every manager will negotiate. The store by me will wheel and deal on most things, others in Utah won't have any of it. I've found Sunday afternoons to be the best time as stores are mostly dead. I love negotiating and rarely if ever pay full price for anything - including "always MSRP" Apple products.