I don't think so!
-When I had one child, I bought name brand diapers.
Now I have three children and I buy Walmart brand and I've found no difference in quality, especially when I don't have newborns.
-When I had one child, I bought new clothes for him as often as I could.
Now I have three children and I buy new clothes when the sale cost for three items is as much as the normal cost for one item. In other words, it rarely happens.
-When I had one child, I could leave the house any time I wanted to as long as it wasn't nap time...and leaving the house usually involves spending money somewhere.
Now I have three children and every time I think, "Oh, I need to buy a ____," I remember how hard it is to take all three boys somewhere, how guilty I feel leaving my husband with the boys at the most tiring time of the day (bedtime), and how much I don't like trying to shop after kids are in bed but before stores close. I've found that most of the "oh, I need to buys" are actually quite unnecessary.
It's like money in the bank!
...That is until we start paying for all three boys to play little league, soccer, music lessons. Oh, and that little expense called college. Missions. Teenage boys on our car insurance plan.
I know kids are expensive, but it's not as bad as many people make it out to be. In my opinion- if you can afford one, you can afford more:)