One issue here is though, if you really want to be a doctor, you need this education, you can't just start as an assistant/ secretary or hospital cleaner and work your way up.
Whereas say a career as a programmer, there are plenty of back doors and ways to learn and move up without having to get the formal education. There's still the reason to get that education but I can honestly say if I don't end up making back the difference on what I spent on it during my working lifetime it won't worry me at all.
The interesting bit is that, at least in the U.S., one can go to decent schools relatively cheaply. In-state tuition at state schools is anywhere from 1:4 to 1:12 ratios with private and out-of-state schools (that is to say, a person could get an entire B.x. and M.x. at a public school for about the same cost as a semester or year at a private institute).