in a free market i cannot see why scalping shoud be illegal. Ultimately, people should be free to sell their property at any price they deem fit. Likewise, buyers can either accept or refuse the offer based on whether or not the event in paticular is worth attending for the increased price.
Often times whena paticular products' run is sold out, it goes up in value as it is no longer available in traditional public venues.
How is selling a sold out ticket at twice its original price any different from selling an issue of Uncanny X-men #1, which was originally 12 cents, for $25,000?
But what about legal agreements. As in, "you may not resell this" plain and simple. It happens all the time, should tickets be exempted?