This isn't necessarily support related but I see questions along this vein asked with regular frequency so I thought that if you haven't seen Gartner's report titled Quantifying the Value of Microsoft's Desktop Optimization Pack then you might be interested in giving it a read. Since SoftGrid/App-V is part of the Microsoft Desktop Optimization Pack (MDOP) and to get MDOP you need Software Assurance (SA), this information should help you assign a dollar value to the various components that make up the MDOP package.
You can read the report here.
And while we're on the topic of SA, they also released a similar report titled How to Quantify the Value of Software Assurance for Windows Client. I won't spoil the surprise by telling you their conclusions here so if you want read it you can view the report here.
J.C. Hornbeck | Manageability Knowledge Engineer