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tickets for sporting events, concerts, etc.

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Ticketmaster does this, usually for first 3-8 floor rows of a big concert, depending on the venue. Prices tend to range from 2.5x-1.5x the highest regular printed ticket price as you move back. That figure is just based on my experience looking at tickets - I don't know if it holds true for all auctions but I'd guess it's something like that.