Yes, but it might be cheaper to build when the time comes and it will still be very good by your current 'old' standards. You just have to ask yourself what you need the computer for and whether having the latest specs is really that much of an advantage to you personally. You'll certainly save money by staying slightly behind the state of the art and you may even have more enjoyment from it, since the hardware is already tried and tested. With brand new technology, you don't know what it's shortfalls are until they hit you and you've already spent your money. Even then, whatever you have will probably be going out of date as you're building it.
And do remember that 'best' is subjective. What's actually best for a given task may vary, from user to user. I would say it's best to assess your needs first - then build a machine which will fulfill them.
Just my two cents...
Dr. V