If you had a steady job, would you have children? Because of the warm fuzzy feeling of having children? It's real I know but it's gonna write off at least 15 years of your and your wife's life, yet the warm fuzzy feeling is real. If that feeling is what you really want, do it. Get a higher paying job and do it. i personally didn't know the extent of it but knew it would take a lot of tears and sweat, still I wanted that warm feeling of a child (two!). I took that plunge and I had no steady income so I figured things out.
Expectations from parents and relatives, honestly if that is your reason then just get a vasectomy. Having kids because others want you to, is just stupid.
Lastly there is nothing wrong with not having children at all. If you don't want, just don't have em. Esp if you're wife doesn't want a child.