Side note: I don't understand how someone can think $150,000 or more a year is a little amount of money. I've seen people have more than they needed with $50,000 a year salaries. it all just depends on how much you want to eat at that $50 a plate restaurant each week. I'm not saying money means a whole lot to me. I'm simply confused by the claims made here.
Geographic location makes a difference. Where I live, you can rent a 2 bedroom house for approximately $1,200 a month. I can easily live a "basic" middle class life making no more than $30,000 a year. Many things you see people mention in this forum are unnecessary, and even if they are, you can get everything much cheaper.
I currently pay $80 a month for food, at most, $30 for internet (faster than basic broadband), $50 for electric, $900 a month in rent for a two bedroom house with a decent yard, and other smaller fees. Even in a generous model of $1,500 a month in expenses, that only comes out to $1,800, which is less than half of a "low" end salary. You figure even with a starting salary of $40,000 the taxes will be 25%, reducing that to $30,000. Divide that by 12 for the per month salary and it's $2,500. That leaves you with $700 per month to spend on whatever you want. May not seem like a lot, but depending on your location, salary can be significantly higher. I've seen computer science undergrads make about $50,000 a year coming straight out of college without experience.
But, if you're in any career for the money, my advice is to stay far away from Biology or medcine. For ungraduates, Biology can be one of the lowest-paid and longest to gain universal recognition fields. My brother's friend (granted he made about a 3.1 GPA), was offered a job making $12 an hour dissecting mice with his B.S. in Biology. Yes, $12 an hour. Any person with experience can find a job not requiring a degree for a higher hourly salary. In fact, the Sears store I used to work at for a large portion of my freshman/sophomore years, paid their 2nd lowest ranked employees almost that much money. To get any sort of decent salary with a Biology degree, you will need a PhD. Computer science majors with a B.S. and a few years of experience make more than PhDs in Biology (Google and Facebook can pay $90,000 a year.) These facts can't really show any sort of significance to getting a degree.
Then medical school, as the primary poster mentioned, hardly seems worth it. Sure, some physicians can make $300,000+ a year, but that's almost always after years of work experience and hard-earned recognition in the field. The youngest a person could possibly finish his or her entire medical education finishing high school at 19 (let's use oncology as an example) is 32. That's 3 years for the bachelor's (with AP classes in high school to cover general ed), 4 years for medical school, 3 years of residency, and 1 or 2 years of a fellowship, especially for neuro-oncology. Then, without any experience, the salary can be as low as $120,000 a year, with 28% taxes. This doesn't count the fact that medical debt can be staggering, almost more than a beginning physician's salary. It will take another 10 years to pay it off which, in this model, puts the individual at about 42, with maybe netting around $200,000 a year at age 45. The taxes put you back down to $140,000, which can be about the same as a very successful computer programmer who received an MBA, or physicist (according to the Bureau of Labor Statistics, the highest paid ones receive more than $160,000 per year.) Yes, a PhD is needed, but that is minus any MCAT requirements and the general stress of medical school.
Money isn't everything, but that much time invested deserves a much greater turn out. Yes, I am aware there are some people who naturally want to help others, but medicine isn't the only route to go. There are many other disciplines within that field that require a slew of degrees: physics, mathematics, computer science, and even business administration, which all work together to make primary care much easier and more efficient.
In a nutshell: Doing medicine just for the money isn't worth it in terms of time investment, but your life certainly isn't going to be impoverished with a $40,000 a year salary. Just be happy doing what you want to do. Being excited to enter work every morning is much more imperative than putting up with something so you can make payments on a $60,000 a year car.