Not cheap enough. I use apache all the time on not all that new hardware, properly tuned it works. I have a home server that hosts various things for myself and friends. It wasn't much but it happily ran multiple different websites/forums/wiki via Apache, some MMO, a bunch of databases, some file storage, folding@home, and much more besides.

When one of my hosted sites wanted to move to wordpress, I needed to upgrade the memory fourfold, the CPU several generations, to accommodate one instance.

There exists tutorials and mods all over the internet for making Wordpress less of a burden, I'm skeptical they'd exist if it didn't waste resources.

I won't mince words. Wordpress is a pig.