Conversely they will not pay UOR cash if they think that it is a way of shortcutting/ part funding what is actually a core requirement.True. Which has an impact on long term management of big, complex weapon systems that need parts and updates.
HMT might stump up for the purchase of a batch of Mastiff off the lot, but the log chain that comes with it? Wheels, gearboxes, engines, axles, etc? They won't want to keep paying for that. They will, quite rightly,say
"We bought you the puppy. It's up to you to walk it feed it and pay the vets bills."
The other feature of UOR is the Taking The Piss factor, making any purchase outrageously expensive.