As for ROI, there are studies that will more than support the purchase of a DM suite. Gartner's "Desktop TCO Update, 2003" cites a three-year total cost of ownership for an unmanaged Windows XP desktop of $5,309. The same desktop when well-managed--defined by Gartner as implementing a raft of best practices combined with appropriate tools, processes and policies (read: a full-blown DM suite)--is $3,335.
There are four major metrics to realizing ROI:
Productivity gains: Information workers with more reliable systems and faster tech support are more productive.
Software-license management: Avoiding the overpurchase of licenses or evading an audit may yield an immediate ROI. Don't fall into the "An audit will never happen to us" or "We're compliant even though we can't prove it" trap. The risk of an audit is very real.
Reduced administrative expenses: These expenses include the cost of rolling out new software, upgrading existing software, capacity planning and asset tracking. Organizations with many legacy systems, diverse hardware or remote users may have a hard time keeping track of their desktops, and a DM suite can help target specific computers based on inventory data.
When switching vendors or hardware platforms, DM suites let you target updates to specific systems. For example, you can easily distribute a BIOS update to all Dell OptiPlex systems, or new NIC drivers to Compaqs that are running Windows 2000 but not XP. Performing such tasks with login scripts can get messy.