If having children are a priority, then you ought to make life choices to support that priority. It's frustrating when people who made the choice to not pursue further education (college, trade school, apprenticeships, anything), choose not to stay with a job long enough to move up the ladder, and choose to live in areas without jobs or areas with high costs of living then complain about not being able to afford kids. No, you chose not to be able to afford kids.
We all have things we value in life. For some of us, it's pets, a nice house, leisure time, time in nature, a family, whatever. Whatever it is, we're responsible for making the choices that make those goals a reality. If you choose to not go to continue your education in any way and only pursue minimum wage jobs, then in my mind you should not be choosing to have children.
My brother-in-law has never wanted anything more than to be a dad. Yet he screwed around in high school, didn't want to apply to college, and has worked minimum wage jobs for years on and off (he'll get bored or frustrated and quit and get a different minimum wage job). He really wants to be a stay-at-home dad. His live in girlfriend is an art major though (not exactly a high $$$ field). The choices he's making in his life are leading him to where it would be very irresponsible to have children (many months he and his gf are barely paying all the bills--when emergencies come up, he has to borrow from mom & dad). If he had a kid right now, no one would be pleased with him...just not the right choice to make.