The difference between Apple and Windows PC used to be parts and cost, now it is mostly just cost. Since switching to Intel, Apple are just mid specced PCs with really nice styling. The only place Apples innovates and leads in the computer market is in it's unibody laptop designs and it's displays, the rest is just overpriced tosh that people will buy because, like you, they think they're investing.
A computer for ANY consumer level application is not an investment. It's old hat as soon as the next model is available, which in the case of Apple is usually within six months. There are Windows PCs that ran XP that can be upgraded or just run Win7 out of the box. That is an investment. After a few product generations, Apple ditches its customers and forces upgrade. That means buying a new system, since they make it a song and dance to open anything with their logo on it.