I hear what you are saying. What I'm interested in exploring the consequences around rational behavior should if you make the assumption that (a) each unit of G

I hear what you are saying. What I'm interested in exploring the consequences around rational behavior should if you make the assumption that (a) each unit of GH/s has a certain cost, (b) the miners are expecting to recover this cost, (c) for an ethical player this cost can be recovered through the sum of the block reward and transaction fees, and (d) an unethical player could also attempt to recover the mining costs by performing a double spend attack. My question is for what transaction values does (d) become a viable and rational strategy. The reason I ask this question is because mining is hugely more expensive operation in comparison to a centralized transaction processing system. It is way more inefficient to have hundreds and thousands of computers chugging away trying to shove a SHA puzzle than it is to just do a simple atomic database update. So somebody must be paying for this and the question is who? And what is all this really costing them. And from this, the next question that follows is what is the impact of the mining reward/cost on what can be secured by the network? So that is the question I was really trying to get at. I'd be interested in hearing your thoughts on this or pointers to analyses along these lines.