Gail,
It really depends on the attitude and maturity of the kid (recipient) and how we deliver the message. When you just give the number, it does not mean much but when you compare with different variables and examples, the kids would understand especially our kids.
When someone says Antarctica is cold, many kids will agree and leave it at that. Many of our kids want to know how cold (lowest temperature) and what kind of animals survive and how.
When the kids understand more about their own giftedness, they (hopefully) will gain more humility and empathy.
In our state, the 7th graders are encouraged to go to state website that discuss different careers (what they do, how much education they need and how much they make). They should have some idea of what they want in life so that they can choose extra HS courses (especially for AP classes, etc..). So, the kids at teenager maturity will learn how much you make on their own (if they want to with the google a click away). When you compare how much you make in your profession against other profession that they know, that information hits home. And when you talk about how often (each profession) can go to restaurant, what kind of car they can buy, house etc.., the message get acrossed. (It is kind of unfair because I have seen so many people buying the houses and cars they barely can afford).