She moved her family from the US to South Korea with her first pay cheque!!!

It must have been a huge amount. I think some idols are paid better than people think.

Quote from jimeous

Some Trainees do get paid from work they do for the Company, Somi is probably the most famous trainee for this but other Trainees of JYPE have had paid work as JYPE has enrolled some of them in Modelling Agencies, JiHyo, Jeongyeon and Nayeon are examples.

This is very good for them. It makes their trainee life meaningful.

Quote from Popper-of-Ks

I think it goes without saying that some idols are filthy rich, and that you're going to at least have a decent living as long as you're moderately successful. There's inequality amongst idols, just as there is in any other profession, but people tend to underestimate what more successful idols earn just because they've heard horror stories from those who didn't make it.

People also don't realize that a lot of idols come from families that were already fairly wealthy to begin with, and I think Jessica was one of them (buying a home for them in Korea was a nice gesture, but they already lived in one of the most expensive cities in America.)

This is true.

I was searching about the upcoming TVXQ concert in Japan and saw that they had already made over $100 million before any other Kpop group was reported to have made that but I don't think they are ranked among the richest kpop idols.

For Jessica, I've always thought that she was raised in a middle-class family seeing how she had ballet classes and afforded vocal training and piano lessons together with her sister. Which makes it even more surprising that her first check was enough to help the family settle back in Korea because it had to be enough for them to match their standards of living. They even had a pool which is not cheap in Korea.