@Fa5t3r - It's not impossible to make your own gaming laptop, but I don't know how much cheaper it would end up being, since a decent graphics card is always going to be very expensive. That's what drives up the price really. I've seen them for thousands of dollars and a custom gaming laptop can run up to 10,000 if you get every kind of bell and whistle.
Whether it actually needs to have all those extras in order to play games well, I don't know. I'd rather spend that kind of money on the games themselves.
But I have to admit I really like the LED light displays that gaming laptops always seem to have. My favorite was a mouse that looked like it was made out of lava because of some red lights in the grip.