Sure it will last 4 years or more (my old mac plus still works fine for old games), but it is only really fun for 2 years. and that is why one should sell it after 1,5-2 years for more than half the price it was bought for and buy a new one.
that way it is an endless joyride!
congratulations to the posts! i have been at it for more than three years and just recently got past 800.