Is this actually happening? A bunch of people buying something for cheap and then immediately selling it for what the market can bear isn't cornering the market. For that you need a cartel (or a group of people acting in unison) buying the goods up, then hoarding it to drive up the price.

If the producers could produce more, scalping won't be possible.

Scalpers just appropriate the profit which the producers could make if they could afford it. Often they cannot because they declare a price at launch.