It certainly partially answered your question and the rest could have been answered if you provided more accurate info.
I decided to look up the transaction you're complaining, and here's what actually occurred:
You sent 4.049 SBD (not $4.20 worth of Steem as you said). At the time we received it, that SBD was worth 3.61 USD (according to coinmarketcap.com). We then sent you 0.68 USD worth of Bitcoin (again the price is coming from coinmarketcap). So what cost most of the difference between 3.61 USD and 0.68 USD? Primarily our estimated cost of the bitcoin transaction at the time of the transaction. Bitcoin transactions are extremely expensive right now, hence I wrote this post to suggest avoiding them if you're just going to fiat.
It certainly partially answered your question and the rest could have been answered if you provided more accurate info.
I decided to look up the transaction you're complaining, and here's what actually occurred:
You sent 4.049 SBD (not $4.20 worth of Steem as you said). At the time we received it, that SBD was worth 3.61 USD (according to coinmarketcap.com). We then sent you 0.68 USD worth of Bitcoin (again the price is coming from coinmarketcap). So what cost most of the difference between 3.61 USD and 0.68 USD? Primarily our estimated cost of the bitcoin transaction at the time of the transaction. Bitcoin transactions are extremely expensive right now, hence I wrote this post to suggest avoiding them if you're just going to fiat.