The reason for closing that thread was it got rather nasty and off topic. I think this needs to be discussed as its a hot topic and it would be good to talk it out and let everyone air their opinion.
I was just curious about your definition of scalper as I've mainly heard it associated with extravagances like concert and show tickets.
Gouging tends to be used in a more general theme, ie the gas situation and involves a group who have an item in high demand and decide as a group to overcharge knowing that the consumer will have to purchase.
Supply vs demand has been discussed here as well, but its not really relavent as the product is no longer produced. To truly take advantage of the supply/demand theory the seller has to have control of a share of the market big enough to control its flow, keeping it low to raise demand and thus be able to command his price. Its a lot more complicated than that, uber simplified here.
Again, as long as it remains civil, lets talk this out! Dont go away.

I promise I wont get too nasty, economics was a favorite subject of mine in college.