What value will PhD give me?
I am a Mechanical Engineering PhD, Electrical Engineering MS, Bioengineering MS, Electrical Engineering BS in USA. I was an international student and I met my wife who was also an international student when we were B.S. In order to keep our relationship, we stayed in US as students. Last year I got my green card (No green card is very difficult to find job in US, even if international student may apply working visa. Not much company is willing to hire a temporary working visa people). 

Currently, I am a contractor in a small private company. My hourly paid is as same as a B.S. student that I taught when I was a PhD student. My previous labmate who is a US citizen got a government job, the other one also citizen got a position at NASA.  

PhD is almost no value to most of industries. I used my PhD title to get my current job, but this job is totally unrelated to my research. Small and middle size companies do NOT spend time to train you. They need someone knowledge more than creativity. 

If you want to use a PHD title, so that you can a professor. At least in USA, you need to have a few years of post-doc training first. Moreover, there are 400 applications per assistant professor position open in my previous university (Top 100 NOT Top 10).

Do NOT do a PHD if you don't have to.