Anyone else having issues with toxic people more and more?

I was doing a commission for someone and after saying the price will be around 20k they said that was fine. After working on it, spending at least a day and lots of coins finishing it i tell them the final price would be 30k. They get very mad over this for no reason saying all this crap and twisting my words over and over again getting themselves all worked up.. I told them i was 100% fine with waiting on them to get the coins for however long or negotiating the price. Why commission someone that has told you prices very depending on how long and how hard it was to make then get mad when i tell them the price that i have told them before even starting on it. This whole interaction could have been avoided and worked out nicely. I spent lots of coins and time on it for them to just ghost me after getting mad about something that could have been solved very easily.