Scale Out of Reporting Server - Quantifying cost benefits.

Hello Experts,

Am involved in Performance testing of existing system at one of our client.

What we found is reporting server and application database server are on the same machine.

At peak hours concurrent users vary around 350-400 and there are around 250 reports (large reports) and on the same machine database is enabled with filestream.

Plan is to move reporting server to different machine and Filestream to different volume.

But before presenting the report we need to quantify the cost / performance benefits to the client before they can implement the required changes.

Is there any white paper how to make a Quantifying report (cost benefits) for this (moving report server to different machine).

Thanks

Sree