PCs are expensive. If I could have found a pc for the price of my ps3 that could play the same games, I would have done it. It was unbelievable that I was even able to get a ps3. I am an RPG player and truly am a pc gamer, but I don't have a decent pc. Please, help find me a good gaming pc for anywhere close to $400. It's not that simple. My mom doesn't spend excessive amounts of money on luxuries and I can't find a way to make money.
Depends on how bad your PC is. Usually, an Upgrade to your Ram and/or a Videocard will be enough, as well as a harddrive if you need more memory. After about 5-10 years, you may need to upgrade your computer's CPU, and very rarely the OS (only very recently do games require at least windows XP.)
Indipendent components tend to cost $150+, (1 gig of RAM tends to cost $75, but since they only work in pairs, $150.) Usually, the Videocard is the most vital component for a computer, second only to the CPU, which rarely needs to be replaced (if your CPU is bad, in all likelyhood, you need a new computer.)
It's always the most expensive to get a new gaming computer, but once you've got it, you only need to drop a hundred or so every few years into it. Compare that to consoles, which tend to require total replacement for a brand-new one.