I thought I told you that we won't stop
Are you thinking about buying a new system? Of course you are. Hardware junkies are never content with what they have. Sure, you say you just want a few small upgrades, but eventually you reach the point where you want a whole new system. We've been through it plenty of times.
Some try to make our systems last longer by purchasing top of the line parts. This is a logical option for hardware newbies. Buy a top of the line luxury car, and you can sleep soundly at night knowing that after five years, your car will still have a high resale value because it'll be able to perform almost as well as cars produced five years later. That $1000 Maytag Neptune washer of yours is still going to be the best, or one of the best washers on the market five years down the line. That's the world of normal durable goods. We're in hardware land now. Cars don't get twice as fast, or twice as luxurious every 18 months. Washers don't wash twice as fast, or get your clothes twice as clean 18 months down the line either.
It's all about depreciation
Buy a top of the line PC now, and we can guarantee you that you'll be able to get a system that's twice as fast with more features for the same amount of money 2 years later. Remember that $2500 486 system you bought 5 years ago? How much is it worth now? Right, it's probably only worth $100-$300 now, including the monitor.
Trying to stay ahead of the technology curve is very expensive. You're paying a very high premium for goods that depreciate in value very quickly. Intel has a habit using luxury pricing for their high-end processors. The incredible margins on the Xeon and high-end Pentium III processors allow Intel to keep the average price of every CPU it makes above $200.
What should I do?
Don't buy a system that's ahead of the curve. Expensive cutting edge systems are sweet, but they only stay cutting edge for a couple months. You should just concentrate on staying with the curve. It's cheaper, and you get to buy new hardware more often. Pass on that $650 P3-600, and go with the $200 P3-450. You can put that extra $450 into a nice monitor or save it for the next upgrade. Leave the flagship processors to businesses that don't have the manpower to keep their computers with the curve.