At the time of this writing, there are 9 auctions for WWDC tickets on eBay. To be clear, the official price for a single ticket was $1,500.
One auction has a bid of $1,100, with a BuyItNow price of $3,900. Ah, but there's free shipping. Another is at $1,725, with a BIN price of $4,599, but once again with free shipping.
Among the others which have bids are ones with bids of $2,125; $3,000; and $3,250.
Before anyone assumes that Apple will step in to halt these auctions, it doesn't appear that will be the case. A number of auctions have completed, including this one for $3,550.
We haven't looked at Craigslist, but it would be interesting to see what's going on there.