So looking at the Scope and Criteria for the Trending: Sprawl Storage Cost the following is defined by default for the Criteria:
(/virtualMachine/totalStorageSizeUsed + /virtualMachine/snapshotStorageSize) * 15 div 1073741824\
1073741824 is 1024^3 but what does the 15 quantify?
Really what I am wondering about is 15 the value per GB?
You are correct the Sprawl Storage Cost trend estimates the storage cost of idle and stale VMs as well as old and large snapshots and assumes $15 per GB for the calculation.