Laptops wear out. Keyboards go shiny, lose the print, and start to malfunction. Disks get closer to the inevitable crash, and are often hopelessly small. RAM is inadequate. Dust has clogged the cooling system, and need clearing out by someone who knows what they are doing. Spare parts are expensive. The battery may be down to holding very little charge, and a new one is not cheap. They are heavy too, unless expensive.
Unless a full size laptop (screen size mainly) with built in DVD-drive is paramount, I would advice going for a new netbook with warranty.
I've had about 5 laptops in 8 years, all payed for by me, and the next one will be a netbook simply because the loss of investment is miniscule when the eventual upgrade comes along, compared to paying for a "real" laptop. I'll keep my Vaio going though for a few more years (until netbooks overtake it in performance), as it's a great laptop, but I'm through paying that kind of money for what is essentially a web surfing and email tool. (I've played AH about 4 times on the Vaio.)
Well, that's my perspective on things anyway. You may need an external DVD drive, or one on the home network, that the netbook can access. Or, you may never need it at all, depending on usage!
