Capacity planning: "Based on our performance monitoring over the last 6 months, (show the charts you've made) we have 4 systems that will require additional disk within six months at a cost of $x, and two that need additional memory immediately. My projections go out to a year based on current growth rates of our service."
What, you don't have performance monitoring statistics? You'd better start now. And learn how to do projections based on business growth rates.
Bottlenecks: "When we look at the end to end system, it seems that our primary bottleneck is in our backed SQL database. Transactions take 1.2 seconds to complete, while the rest of the system completes in .2 seconds. We'd like to spend $$ on a DBA to go over and optimize the queries."
Costs: "Running our entire data center costs $y per month. The electric company is due to raise rates in 3 months (yes, you call them and ask!) so our costs will increase to $z. We think we can offset that cost by calling the server manufacturers and ensuring that our warranty will cover things if we reduce our air conditioning by 3 degrees. We also have 6 servers coming off of warranty in 6 months. The cost to replace them will be $x which includes migration costs, and the cost to extend the warranty is $y."