Hey Sergey Pshenichkin ,
The book I would recommend before doing anything is Dave Ramsey’s Total Money Makeover. Your friend’s story isn’t far off from millions of other Americans. Dave has helped countless folks out of this exact same situation.
While a higher income is ideal, it isn’t necessary. It is all about making the most of what you have, and understanding what you can and cannot afford. In order to be in the top 1% of income earners in the world, you only need to make $32,400 per year. We are all incredibly blessed and fortunate.
Personally, I accumulated a net worth of a little over 200k without ever making over 40k. My position has changed now, but only because I made the most of every single dollar coming into my home.
My favorite analogy about making and keeping money is that of a broken vase. If you pour water into a broken vase, water will come out. It doesn’t matter how much you pour in, it will be empty. It’d be wise to fix the cracks in the vase prior to pouring in more water. Likewise, one can make as much money as imaginable, if they don’t understand how to retain the money earned, not really any sense in making more money.