Sorry to be coming to this late.

I have a Nintendo DS and LOVE it. I bought it a few years back.

I strongly suggest you get the following (which you can find on ebay):
- screen protector
- extra stylus

Have him put the screen protector on IMMEDIATELY! The stylus will wear out and scratch the screen. I thought I would catch it in time, but nope I didn't. Then I stopped using it for about a week until the screen protector arrived, to prevent any further damage.

Re the screen protector: you will pay more for a "licensed" Nintendo one. I didn't bother with that.