The specific transaction this post refers to was 1813 bytes. It had 12 inputs that had to be signed for making it larger than average. For $10M I'd be willing to manually type out the 3626 hex digits, or if feeling lazy splurge on a $10 USB stick. Only 3 inputs account for almost all of the balance, so really it could have been moved for under 1000 bytes, which I happily write longhand on paper with a quill in triplicate before I'd even consider exposing the secret key to the internet.
