Unless BitPay have changed their policies, the exchange rate is only locked in for 15 minutes. If the transaction doesn't get its first confirmation before then, it expires and if the exchange rate goes up even slightly they consider the transaction underpaid. That's almost certainly what happened here. They used to be more sensible and only require the transaction to be broadcast to them within the 15 minute window, but they quietly changed it a few years back.

> If the transaction doesn't get its first confirmation before then, it expires

I don't think that's true. To the best of my knowledge, they lock-in the rate if the transaction appears on the network within the 15 minutes window, regardless of when its confirmed.

It's certainly possible they fixed this at some point, I gave up on using them after a bad experience with this a few years back. It just wasn't worth the hassle of trying to use Bitcoin for payments, especially after the Humble Bundle stopped accepting it for most things because they wanted to track purchasers' IDs.

That's interesting. Their published terms of use do NOT say that, so if so that's shady as hell.

Bitcoin was a perfectly reasonable way to buy a game on Steam in February last year. Of course my 0.035631 BTC purchase means I could have paid $15 cash and saved the coins and had $287 worth of BTC today. So maybe it wasn’t reasonable.

The fact that you used BTC for that purchase doesn't matter, you could also have decided to buy BTC instead of anything you bought with another currency.

Although in an environment where the main national currency experiences deflation like bitcoin, you do actually see people responding to the incentive by reducing current purchases, which is bad for economic growth.

But then you realise capital gains and have to pay taxes on them. Better to leave your current bitcoin unsold and pay in cash.

It might be bad for economic growth, but an indebted populace with no savings is arguably much worse due to instability.

This is why it's better to pay using QR codes because you can't mistype the amount.

Hi @Lazare, I am the dude who posted that reddit post.

The $25 game cost me 0.00424232 BTC (around $32.96 USD at that time). I transferred that much to them, but the network fees for some reason raised within that 2.5 hours. 3 cents. And they cancelled it. The fees were 0.00038932 BTC

It is messed up. Sending money from Coinbase to BitPay, for $29 resulted in $32 dollar in fees.

Nevertheless, this experiment showing a bunch of friends (~10) why Bitcoin is the worst payment provider. Network fees are not calculated correctly, transaction fees too. And at the end, this 3 cents difference from the transaction fees made a big deal.

And worse of all, customer support doesn't exist for the consumer at all when they pay for Bitcoin.

Yeah, it seems plausible that he thought he had to pay $29 in BTC, and so googled and paid that - but it came out 0.000004 BTC lower. And later when he found that what he paid was now $31, he also thought "well that's more than what I had to pay".

Naw, BitPay tells you the exact amount to pay in BTC for a 15 minute window. Around 10 of my friends verified I paid the right price, I was projecting to the big screen to show how it works. For some reason the network fee to pay the miners screwed up in BitPay or the price they received wasn't the right price since bitcoin went down slightly within 2.5 hours. So at the end of the day, the consumer is to blame.

It almost looks like Bitpay and Steam resolved the price conversion at separate times. Where the upward trend screwed the customer.

I've never used Bitpay, but according to their docs, the process is:

1. The merchant tells Bitpay the USD value of the transactions

2. Bitpay calculates a BTC value based on current exchange rates

3. Bitpay sends an invoice to the customer valid for 15 minutes

4. If the transaction to transfer BTC is broadcast on the network prior to the invoice expiring, Bitpay will honour their initial quote.

5. Once 6 blocks have confirmed the transaction, Bitpay transfers the original USD amount to the merchant

So in this case, Steam doesn't do the price conversion at all, only Bitpay does. And Bitpay only does it once, when the invoice is issued. It appears that the user either transferred an incorrect amount, OR he waited more than 15 minutes to start the transaction, OR (as some are suggesting) Bitpay is being nefarious and not honouring their quote.