Think about it! If you need a pair of salad tongs, the most "green" thing to buy new is probably the stylish Bamboo kind. A renewable resource in abundance, clean production from start to finish, no plastic fumes or byproducts to tear up our atmosphere. However, if you find a pair of used salad tongs, be it plastic, bamboo, metal... #1. You are saving those tongs from the landfill, #2. You are preventing resources from being used in the production of a new pair and #3. Chances are you are contributing to a good cause in the process by shopping at a thrift store such as Goodwill , St. Vincent de Paul or the Salvation Army. (all though, you could also find them for free on sites like Craigslist or Freecycle)
Lets translate that into something related to babies. (because we all know that babies cost a FORTUNE!) babies grow out of their clothes SO FAST! A new born will probably wear the same outfit for 3 months or less before he has to move into the next size up. Those newborn size clothes are still in great shape! No wear and tare, probably no stains if they are washed properly, and what do you do with them when you're done with them? Most clothing ends up in the aforementioned thrift stores, where they are destined to spend the rest of their days on the racks being useless.
SO: the next time you need to buy your baby a new pair of footie pajamas or an easter dress (we all know how many times those get worn before you out grow them) check the racks at your local thrift store, check the local free stuff, and remember: REDUCE, REUSE, RECYCLE!