Need a suggestion of an economical lens for a Panasonic Lumix GF2

Hello,

We just purchased a Lumix GF2 body for our daughter. We overlooked it was a body only. Would appreciate suggestions for an economical lens for that camera. Saw lots of lens on ebay and want to make sure it is compatible. Either a kit zoom or a prime would be fine. She is under a tight budget (meaning I am paying).