Just remember to consider the stuff as a floor "covering" and not permanent flooring. Like carpet, vinyl, etc., it has a life and then you may be tearing and scraping it up some day after you get tired of the scratches, water damage, etc. There are plenty of posts below to educate yourself on problems others have had.
I would think a nice business that sells a lot would take back part of an open box too but don't forget to keep an extra box or so around for later repairs cause you will never match it again. It is always good if DIYers and contractors would have extra and leave leftover items such as tile, shingles, paint, stain, etc., so the homeowner can make the color matching repairs later on. Save all instructions and I personally think contractors should do the same and leave them with the homeowner. It will help a new homeowner also who may have no idea what was installed and how to repair it. Good luck.