girlfriends are expensive and nintendo is cheap! hahaha!

Vincent, maybe this may or may not be what you want. But just to answer your question on what to check before buying a ds lite: serial numbers to have a better chance of avoiding getting a "future" cracked ds lite:

A link here

It means a "cracked hinge", a manufacturing defect on the hinge of ds lites. Due to time constraints, I can't supply a link to pictures. You can find pictures of those on the web.