NFT Gas Wars: User Pays $430k for Failed Ethereum Transaction

We all know the NFT gas wars are becoming more heated by the day, pun intended. But one user’s experience shows just how far things can go, paying $430,000 in fees for a failed Ethereum transaction.

This incredible story of misadventure begins with the Strips MISO token sale. Coming just weeks after DeversiFi’s mistake saw charges of $23.7million paid for a single transaction you’d expect people to be on high alert when it comes to fees. However, that error — which was eventually refunded by the miner — apparently passed by some unnoticed.

For one user, who hasn’t been identified, their error fee experience has wound up costing a staggering $430,000. Far less than DiversiFi’s bill, but thankfully we still live in a world where close to half a million is still considered too much money to throw away. Especially on transaction fees. More so on failed transaction fees.

NFT Gas Wars: How Did This Happen?

The NFT gas wars are mirrored by increasingly stiff (read: impossible) competition when it comes to rapid, high-value sales. With this in mind, many users are looking to work around their rivals. One way to do this is through Flashbots.

For those who don’t know, Flashbots is a communication protocol between Ethereum users and miners. Although a little reductive, we can see this as essentially a form of bribing miners for priority on newly mined blocks. The result of this can mean just enough edge on others to win the sale.

Sadly, though, in this instance, the opposite happened. While Flashbots transactions are designed to stay hidden until they are added to a block, here the transaction wound up in the public mempool. This is where standard Ethereum transactions are stored before they find a block of their own. One miner then processed the transaction into a block, however, the Strips MISO sale had already finished, with all tokens snapped up in seconds. So, the transaction failed, the hopeful buyer received nothing, but the transaction fee amounted to 123 ETH; $430,000.

This Should Not Have Happened

“This transaction was sent to the mempool. You can see here that Etherscan saw it in the mempool. Also, we never saw it in the Flashbots relay,” said Robert Miller, product manager at Flashbots, in a Twitter post. He also points out that if the Flashbots transaction had been processed as it should, this error would not have happened. The transaction would not have accrued any fees if it were not going to secure any tokens. 

Amazingly, the same $430,000 user had made a second transaction using Flashbots. Clearly perturbed by the first, they cancelled the second, but this action also cost them 30 ETH. Which translates as $105,000. An expensive mistake, or rather two, it shows how important it is to understand processes, protocols and systems. NFTEvening has a number of Beginner Guides to help, including what you need to know about gas fees, and advice on the best crypto wallets.