It depends on how you look at it.
I just paid $170 for a Radeon 4870, and it's far and away more powerful than any console on the market.
You might pay slightly more for a PC and the subsequent upgrades, but you are also going to have a HUGE graphical edge over any console. If you just want sports games, the PC is not a viable option, but for almost every other genre, PC is far and away better for graphics, control options, and flexibility.
You can say consoles are cheaper because you don't have to upgrade them, but what do you call buying a new one every 5-6 years? A new console is usually more expensive than a good graphics card, and not as powerful.