I have received an offer for my late 2008 Macbook of around £400 and I would get a 8% discount on a new Macbook, which would mean that I can buy a new rMPB 2.6ghz / 512GB ssd for £980. I invested quite a lot in my Macbook Unibody, upgrading the memory to 8gb and buying a 256gb SSD + optical bay with a 7200 1TB HDD. Additionally, the battery was replaced two years ago. This machine runs fine, but I believe that £400 is a very decent offer for a 5 years old machine - I'm not sure I would get such offer again in 6 months or so. Do you guys reckon its a wise thing to upgrade now or to wait?