I'm about to start an MBA program within the next year that's about $40,000 in tuition - that's BEFORE living expenses, and all the other associated costs. Plus, it's in a completely new city / country.
Needless to say, children will be the LAST thing on my mind for the next 8-10 years. And I'm 25. I'm just too selfish to think about having a kid with my girlfriend anytime soon... and that's the way it should be. If you aren't 150% ready to deal with the consequences, DON'T DO IT.