Here's an interesting anecdote:
We rented a baby scale several weeks back to help us with baby's weight-gain problems. When the time came to return it, I vacillated on whether or not to rent it for another week - but the added cost made me decide to send it back instead.
When my husband mentioned my hesitation to the breastfeeding-shop owner, he (the shop-owner) said that it was probably a good thing for us to return it - because he has seen mothers develop unhealthy attachments to their baby scales, something akin to an addition. They start weighing their babies compulsively (and constantly) and have a really hard time parting with the scale. He said that he had one woman keep her scale for nine months, and only returned it after her husband forced the issue (he called the store and begged them to ask for it back).
Of course, none of this applies to me. I was only weighing baby three or four times during a feeding, and maybe twice in between feedings - nothing excessive, you see. And I would only have kept the scale for another week or two - or six months at the outside. Really. And I'm only hyperventilating slightly at having had to return it. And I can easily visit the breastfeeding store without wandering near the baby scale section. More than once or twice, that is. Mmmm.... Baby scales.
But I don't have a problem. Really.