Comparing software with 'Walmart' products is not possible.
When you buy software, you will not get a 'cheap' made version of it... Or has more bugs or something else.
With food, or tools someone can always make a cheaper version. More plastic, less graded metals, more fats and sugars in food to replace expensive ingredients.
With an office software, the retail at 100$ is the same as that reseller online website selling it for 1,5$.
Same code, same version. So how can we judge what is 'legal' and what not ?