MD, PhD
In my field, however, people usually don't get a Ph.D. to teach. In the medical sciences its usually because you want to conduct your research in your own lab, which hopefully you will be able to get finding for through NIH grants (and now, more and more, some private industry funding but this can get complicated with conflicts etc).
But it is very true about coming from wealth in order to be able to put the years in. Big Ach - the stipend isn't much to live on if you don't have additional sources of income such as a significant other working full time or family money. It can get very tough if you plan on staying in academics. Despite the years of financial struggle, if you truly love what you are doing you will be very happy. I certainly was. It isn't the poverty that gets you but sometimes it is the politics. Politics can be intense in academic medicine. The prize isn't money for us, it's the power that comes from departmental advancement that, despite the titles, don't pay much.
I lost my appointment last year. I had no savings as I lived paycheck to paycheck while a resident; never suspecting I would lose my job as I did. Here is how brutal my finances were/are - about 6 months later, I got mugged at night walking to a small room I had rented in a part of town that was cheaper than where I used to work. I got beat up pretty badly, and especially, my mouth was a mess. Months later, I still needed extensive dental work. Believe it or not, I actually PMd back and forth on here with a member who was trying to help me find some kind of work working for an online bb company. He was very cool and tried his best but nothing came of it. I still look a mess and haven't had much interest from other universities in my line of work unfortunately. This is after putting in 10 years of academic post university study (4 years medical school 3 years PhD + 3 years residency prior to termination). I genuinely have nothing to show for it at the moment. So yes degrees are fine and all, however, just realize the tenuous nature of years of study prior to any financial security. It is a risk if you don't come with a safety net of some kind such as family support of savings. Your education actually, believe it or not, can ostracize you from the real world later. It is tough to go back and apply for a regular 9-5. Employers think there must be something wrong with you since why would an doctor be applying for a minimum wage job? I guess they have a point.
Life isn't always a meritocracy. Always have a backup plan. Don't end up like me. A total loser.