Recently, we stopped by the local Wal-Mart with two items in mind: some anti-perspirant for me, and some new sewing needles for the misses. Expected cost - around $7. We didn't stick to that list. We bought a number of other things, things we had been talking about getting, a couple of impulse buys, but really only one other necessity, that being a small package of diapers for the little one.
All together the purchases totalled to $52. Of course, this isn't an unusual occurrence, but it sure makes me take pause and consider the cost of not sticking with just our needs.