For example, if you buy a Samsung TV at walmart, it is the same one you'll
buy at worst buy, only it (usually) costs less and it's always right around
the corner so you don't need to use as much gas (and the dreaded carbon
footprint) to find a worst buy all the way across town.
That's actually wrong. If you look at the serial numbers of the products you buy at Walmart, they are a different series. The products are cheaper because they are slightly inferior. In fact, Walmart often sell products which are specially manufactured only for them, to keep costs low. You don't notice because Walmart have purchased the right to market their products under the same brand name.
When any electronics device is built, there are design specs which call for certain components. These components exist in different grades, which aren't the same price, although they are often interchangeable. The same is true with
other goods, eg the screws might be low grade / inferior quality on cheaper items.
For example, if a factory makes an LCD panel, there may be a small number of pixels which are dead on some of the units. The factory sorts the otherwise identical LCDs into low grade (a few dead pixels) and high grade (no dead pixels), and sells the low grade a bit cheaper. You can build the "same" TV with low grade or high grade components, and the price will be lower or higher. Sometimes it's also convenient to not include a particular component from the initial design, for example in laptops or tablets there's room for a GSM modem, but it isn't always included.
Manufacturers like Samsung keep track of the exact contents of your TV by giving it a special serial number. Maybe to you two TVs look identical, but if you know how to read the serial numbers, you can tell which one has higher quality components or extra features.
So no, Walmart doesn't always sell the exact same products other stores sell, and yes, they often sell a lower grade version of the same product - and that's a major reason why it is cheaper.