My laptop is a few years old, and running slowly. You suggest upgrading memory to speed a Mac up. Am I better off purchasing a completely new one rather than simply upgrading this one?
A Mac should last at least 3 years, the length of the extended AppleCare agreement. After AppleCare expires, you will have to pay for repairs. On a laptop, unless you’re skilled or intrepid, this is going to include parts and labor. Let’s ballpark the average likely repair — from a $200 hard drive to a $900 logic board — at $550.
Now, you can find a good, slightly used Intel Core 2 Duo MacBook on Craigslist for as little as $600. I used not to recommend that people buy used Macs, but the Core 2 Duos are just fantastic machines, and any one that can be upgraded to 4GB RAM is good enough for me or for almost any of my clients (the ones who don’t do serious graphics or multimedia production). If you do opt for a second-hand Mac, please make sure it is either covered by AppleCare or eligible for it, being younger than a year since original purchase date.
That said, I still place a lot of value in buying a new Mac, or one of Apple’s great refurb units.
When should I buy a new Mac?
My standard spiel (which usually starts with the words “my standard spiel”) is this:
After 3 years, you should have a new computer in your budget. After four years, be ready and willing to lay down some jack for a Mac. After five years, your Mac is past its prime, and will not be up to whatever awesome software Apple and other developer/magicians will have concocted.
Is it likely that a simple memory upgrade will solve my speed problem …
Yes, but depending on the model, a G4 Mac can, at most, go up to 2GB RAM, which is too little for modern computing.
… or would you expect others issues to be involved?
Check this post on slow macs and the spinning beach ball to learn how to use Activity Monitor to troubleshoot your Mac.