I agree that it is weird to compare the two as they seem somewhat different.
My
forum (by itself) served almost 15 million page views in the last 30 days, and we just upgraded to a two PHP server (dual clovertown, 4GB RAM each), one mysql (dual clovertown, 4GB RAM, RAID 10 15k scsi) config. we didn't buy the hardware outright, however, so costs can't be compared directly.
I don't know what the capacity of this server setup is, but I would think there would be a lot of room to grow on it. 30 million a month? dunno... guess we'll see.
arn