How can I calculate costs of deploying 1000 instances of Drupal?

What are the things that should I investigate for making an estimate of the cost of deploying 1000 instances of Drupal, for example?

I was thinking in:

• Database space

• Database usage (in ops/second? how can I test it?)

• Application uploads space

• Application processing time (again, how to measure?)

• Bandwidth usage (for medium/low traffic sites)

• DevOps / Technical Support time

This is all about bringing a SaaS platform. Is there anything else I should take in consideration?

How can I know how many "instances" would be able to run in a single host? Much like a Shared Hosting

Would Amazon EC2 / Google / Azure be cheaper than having dedicated servers?

In reply to 'Would Amazon EC2 / Google / Azure be cheaper than having dedicated servers?'

I've done a lot of investigating into this and in every case they are NOT.

80 Linux servers running 24h/365 - annual cost:
Total cost per year
Google £37,515.46
AWS £29,196.53

These costs do NOT include data transfer.

You can buy a dedicated cloud appliance for less than £50k, fully supported, that will run more servers and last you 3 years (min).

StackExchange DevOps Q#1036, answer score: 3