This is a valid and legitimate definition of scalping, but in general I think most people considering scalping to be intentionally buying scarce items for resale at inflated prices.
This is where I need to disagree with you. Sometimes people are looking for out-of-stock, discontinued or hard to find items. In those cases MSRP isn’t even in the equation, those prices are simply market driven.
In my business, the “cost” of selling those spools on ebay probably isn’t simply what I paid for them, it’s also the overhead of the order fulfillment (which in my case as a single person business is substantial). What would be “silly” is selling them at retail, either I should cover my costs by selling them on ebay at a price I can make a profit on or throw them away.
Or, find some way to convert it into something that will make you a profit. One of the things I also market are Resin Art things, and sometimes the parts being made fail, have bubbled, look terrible, and cannot be sold. But, instead of throwing them away, I reincorporate them into other object I make. I have skull molds, and sometimes I have smaller items just just came out bad so I dump them into the mold and make a skull with the items inside, like Dominoes, or game pieces. It not only allows me to not waste the material, but also allows for less material to be used in that mold.
Try to somehow get on Facebook Marketplace of Greece and see for yourself. Im seeing people selling Bambu PLA for 24 which is the normal shop price you find that filament here. What do they earn? they order in bulk from bambu for 10 euros and then undercut actual 3d shops by 1-2 euros. they sell at 22-24 and voila… profit…
Im buying from an official and amazing reseller, but even with that sometimes I struggle to find ABS-GF, especially in black and any other colour available other than yellow, woodgrain plas are gonne forever, petg-cf is appearing and disappearing like an aurora… and thats all for black, most of the times the interesting colours are sold out before even hitting the selves…