Buy the Maintance plan,
make sure it needed / exercised shortly after it is purchased, just before the budget review, and make sure you get a estimate from the support people wha tit would have cost to do the work without the maintance plan. Then claim the difference as a cost savings.
"Next time include maintenance in the original budget, Dilbert. You should know better. "
That works until the vendor changes their maintenance plan to "per core" or based on RAM, memory, VM hosts or storage. (Hello VMWARE, IBM, Microsoft)