The economics of continually selling a product for under its market value? What are the economic principles behind a company continually selling a product for well under its market value. Continually here expressing that it does not appear to be some short term method to bankrupt competitors.

I am talking about companies that sell products that can be routinely resold on the second hand market for many times their initial cost.

I recently watched a documentary on Nike, where it describes their humongous Limited Edition department and how they sell shoes for a few hundred dollars a pop to client base willing to wait in line for weeks and pay thousands of dollars for any one of their limited editions shoes.

It describes Nike underselling their shoes by 1000% in both quantity and price. But Nike is hardly the only example, a few years ago, anyone who wanted to buy a Nintendo Wii could be certain of making a profit reselling it.
1st of all, you should distinguish cases from the Nike case and others, if any:

Since Nike sells only a tiny portion of its shoes "irrationally" it cannot be seen as market value - equilibrium price, but rather as marketing expenses

Think that simply generating a rare nike products market adds value to the brand and motivates consumers to prefer nike

Regarding any other case: they can either be "dumping" - that is selling at a loss in order to throw your competitors, selling above your *average * cost, meaning making  a profit, maybe fightinv for market share, or being cross funded by different activity, to hurt competitors in the subject market