When you registered with ebay, you indicated you agreed to abide by the User Agreement which states:
"While using eBay sites, services and tools, you will not:
fail to deliver payment for items purchased by you, unless the seller has materially changed the item's description after you bid, a clear typographical error is made, or you cannot reach the seller; "
When you clicked on the buy it now button, you were taken to a second screen. By clicking the commit to buy button, you did just that, you commited yourself to buy and pay for the item. That second screen was where you confirmed your commitment.
It will be up to the seller to cancel the transaction.
Non paying buyers deserve unpaid item strikes.