upgrade a notebook wont be a good idea to invest...
notebook can be upgrade, but the cost is likely to be hefty
and by cost it is not only in term of money...
to me, get a good spec notebook today can already last you a 3-4 years...
do not forget, hardware is always a few miles ahead of advancement in software.

sadly but to say, it does not make economic sense if laptop comes into AP..
remember, laptop has far higher problems than a handphone, and it is not something anyone can anyhow learn to fix. manufacturer warranty is pretty much a must to consider when purchasing a laptop
plus, laptop would store far more important and sensitive data than handphone...you do want it in a good hand when it comes to repairing and fixing....