This connects nicely with Dan's article from yesterday [1], if only tangentially. I think a good habit is to instill a mindset whereby there is a single metric for cost, possibly associated with your main product, and keep track of that cost as it relates to your infrastructure spending. I've seen it before work well. For instance, if you sell computers, the cost could be, we spend $100 on infrastructure per computer sold, and engineers can then argue for spending more effectively.