A couple of points from my perspective...
We spent at least $30,000 to concieve our twins (DD1 and DD2). That included 10 monitored IUI cycles, some injectable cycles, and finally IVF x 3. My insurance paid an additional approx $10,000. We were able to pay those costs off within about 3 years.
For this pregnancy we went right back to IVF, it was a $26,000 flat fee (we had to use an egg donor). We were fortunate to have really good credit and a lot of open credit card space. Some people would say we're idiots for spending so much money to have our children, but we examined very closely all of our options and for us the debt was not the issue. We would rather have these kids than a big house or fancy cars.
So when I was doing the IUI cycles several years ago, my cost ranged from $450 - $1000 per cycle depending on the level of monitoring.
Lex - you're totally right. We spend about $12,000 a year on childcare for our twins, and that is only for 3 days a week. Anyone can tell you that kids bring expenses into your life that you wouldn't have otherwise. I waited until I was in my 30's to start TTC, and ended up with horrific medical bills and procedures. I often wonder whether that would have happened had I started in my 20's. But I put it off b/c I was waiting for more financial stability. Therefore, I don't advocate waiting, either. DP and I know that we are never going to be monetarily rich, but our lives are so much more rich thanks to our kids. I wouldn't change anything.