I was just asked today where to get an HDMI cable. My recently purchased Roku didn’t come with one. So, it’s a good question. The answer is, do you want to pay $40 or $10? Best Buy, Staples, etc make a lot of their profit from selling accessories like cables. Don’t get your HDMI cable there!
Believe it or not, the best place is TJMaxx, Marshall’s or Ross. Their stock of HDMI cables is low, but most stores do have them. And that same cable heartily stocked at the electronics stores for $40 is now marked down to only $10.
May I ask, where are you from Eric? From the stores you have suggested I would guess the USA? In Australia there aren’t too many physical stores to get HDMI Cables from at decent prices. Almost every major retailer is out to price gouge on this type of accessory.
This is why most of us shop online for this type of product. Personally I get my HDMI Cables here: http://www.spacehifi.com.au/hdmi-cables