My friend's guilting me into giving up confidential information; What should I do?

They ask….
 “You’re my best friend and I want to apply for this position that is the same rank as you and I know I’m qualified, but don’t know how much money to ask for… How much money do you make? ”

You think to yourself, I know I make much more than they think I do. 
 If I tell them, will they get upset and throw my personal information out to the world?
 But if I don’t tell, will they say we’re no longer best friends and degrade me in front of others?
What should I do?

Listen to The Stoicess' words for some unique advice.

https://stoicmatchmaker.com/