I gave it some thought and overall I'm happy my kids have happened relatively early. More than money or anything they need your energy and enthusiasm. As much as I complain about the lack of time, I think it's better than lack of energy and stamina. At least that's what I extrapolate from my experience so far.

For example, even between my two children I noticed that with the second one I've had sleeping issues, while with the first one I couldn't understand what "sleepless nights" everyone talks about. Like, a newborn kid at night sleeps 50 minutes out of every hour and so did I at the age of 25, being fresh and well rested in the morning. Didn't work as well at the age 31. Can't really imagine what it must feel after 40. And in general I would prefer healthy sleep over money and time.