I understood the British forces view was that the cost of shipping them back from countries such as Afghan was prohibitive, mainly because its land locked and moving them overland to a port to bring em back totals a good percentage of the replacement cost.
The Wolf fleet over here is approaching 20 years old, whilst the earlier stuff (2.5 diesel 90's and 110's etc) is being sold off in earnest whilst the Wolfs are creeping onto the market, they're supposed to be in use for another ten years to boot.
Slightly unrelated but a good illustration of outdated equipment; The Snatch armoured Defenders have caught a lot of flack due to the number of guys killed in them.
The one thing the news agencies kept missing out on was the fact that the original ones were designed to operate on the streets of Northern Ireland and be effective against small arms and whatever improvised explosives they used at the time.
Personal opinion on that one was that they stood up pretty well to the conditions in the deserts, especially as they were up against totally different threats.
Military equipment in the modern world needs to move quickly to keep up, just look at radio equipment...

