When my daughter (at the time 10) asked for a pet gerbil, we saw it as an opportunity for her to grow in her since of responsibility. So, we said she could have one if she saved her money up to buy cage, etc, and the pet. She found an add on craigslist, called (very nervously) the owner, politely navigated the conversation and negotiated the price down from $20 to $17. We met the couple selling the cage at a public location and they were so kind and so impressed with her they bought her a gerbil to go along with the cage. Surprise! And this by total strangers.