Wal Mart will honor the price of any other store... So Wal-Mart.
Price compare the two (Wal Mart is probably cheaper but Home Depot probably has a bigger selection.).
I also find these are great stores as well especially Walmart, however if you want do want to pay higher end prices I would suggest you ask any of these stores for paint that was mixed wrong. If your doing a small room and can get away with a gallon it might be something to look inot. I've done several rooms for $3.00 a gallon fbecause of the mixer's mistake.