That's silly, and also not how it works, at all. You're paying PaaS/IaaS companies so that it's their headache, not yours. Once it becomes your headache, they are no longer doing their job, and you are no longer receiving value for which you are paying for. You don't debit the cost of their downtime from the cost i would've built your infrastructure, you debit the cost of their downtime from your business' revenue and reputation.
Whether or not you could do it better yourself does not excuse the downtime one bit.