But even if they weren't: going from 22k to 50k is a massive difference. People are willing to put up with a lot of bollocks for it. Dismissing that so easily is a really privileged attitude.
"I could already see my salary doubling in front of my eyes"
I thought by this they meant (half jokingly) that this potential employer would double the eventual offer because at that point they had just proved how amazing their skills are. Not that they would double their existing salary, and so it doesn't necessarily imply they have an existing job.