Hmmm, baby boom or just 'every couple of child bearing age' deciding to have kids....sounds pretty normal to me!
Probably just your perception of things has changed as you reach 'the age'.....my wife is pregnant and guess what.....most couples of our age have or are planning kids.
There isn't really going to be any 'extra' costs, just a continuation of current costs (which I agree are too high now anyway).