It's all about the little differences. A $300 is "good enough", to be sure, but that extra $700 will get you slightly faster performance, a higher resolution display, slightly better keyboard, trackpad and battery life.

For something that you use day in and day out and is so crucial to work and life, that $700 starts paying back very quickly. I always make it a point to spend a shitload on my PC - the returns are priceless. Quite literally, it saves a few minutes a day, causes less eye strain, helps me sleep better and get more done. And ultimately, makes my life better in an intangible way.

That said, I'm quite stingy with phones :) Only buy the best value for money rather than the very best. That's mostly because I don't use it very much, only for calls and chat.