The included charger has 5v at 1500mA. A lot of the generic AC/USB chargers I've seen or only 500mA or less. I think my Kindle charger is around 800mA. So I would take the generic one back and use the included one as it will most likely charge the 950 faster than the generic ones. The generic ones will often work, but being lower in current (amperage) they will take longer to charge the reader.

And Best Buy is really bad about mislabeling items and prices and not automatically matching the price listed on the web. I always check the web before going to see what BB has on sale. I usually have to make them look up the sale price in order to get it at that price. Very frustrating, but I guess that is how they survive the retail nightmare in a repressed economy. Always keep checking their sale prices for a week or two after purchasing as well. If they sell the item for less than you paid, they will refund you the difference out to about 15 days, but you have to request the refund as it is not automatic.