E g. In Vienna/Austria a 2-3 bedroom apartment here is about 1-2k while in the bay area it's between 5-10k. If I lose my job I still have a social net that will soften my fall, while in SV you're on your own and can get evicted from one day to the other. We have a single payer healthcare system while in the US certain health issues can, despite being insured, lead to financial ruin.
That being said my salary was until now always a 5-figure salary. In my upcoming job I will for the first time in my career path get a 6-figure salary which excluding bonuses is 70% higher and including bonuses can be up to 89% higher than currently. It took me quite some while to get there, and I can assure others that jobs paying those amounts don't grow on trees. It requires both talent and charisma, and honestly also luck, to land such a job. Constantly switching jobs and chasing slightly higher salaries definitely isn't the way to go.
This is my singular biggest hurdle in going back to school to finish my degree and I'd love to fill the gaps I have around mathematics so I can not only finish my degree; I'd also like to participate in some more advanced computer science that rely heavily on underlying computation.
it really takes you from the ground up all the way to advanced subjects. He published multiple books on various levels of mathematics.