> in many situations 5GB is considerably more expensive then 1TB of disk
> space.
How do you figure? This amount of memory sets me back for less than double the cost of disk space. But *only* if looking at ECC RAM versus cheap & big SATA storage. Go to SAS, as used in many servers, and the scale is more like 1:1.
And that's not even considering RAID, where net capacity is not 100%
Of course, in many environments, you need to get RAM and disks from your server vendor, and they mark up prices arbitrarily ... so your numbers can come out completely different.