The artist was a dumbass for not having a contract and asking for at least something like 1/3 for time and materials and an agreement on a preset price. That's on him 100%.
This is precisely why I don't really ever do commissions, but its a side hustle that I just happen to be passionate about so I have the leverage as its not paying the bills. I do shit I like, if you like it too, we can figure out a price -- it really is rewarding when someone tells you something you created brings happiness every time they see it. Generally, the passion behind the piece and inspiration doing it leads to a product that has quality far higher than some shitty commission piece that you're not remotely excited doing. Granted, there are some classically trained portrait people out there who make a fortune off commissioned pieces. And if you go all in doing this for a living, you do what you have to do, but I dont blame Falxy especially if thats the level of work that resulted. 2,600$ is a fucking joke for that.
I think Mark Carder, an artist from Austin is one of those insanely successful commission artists who charges from 30-60k+ per piece and done portraits of Pres. Bush etc. But those guys are rare.