Originally Posted by 
manic
				 
			Hardly. 
My comments were made from experience owning a TDI and rolling it past half a million km 
Main bearing shells on a TDI are sacrificial, eventually they are due to be replaced. Most people dont own them long enough to get there. On a TDI the procees is almost as easy as popping off the sump and rotating some new ones in place of old. The shells are cheap.
Head gaskets are consumable, you replace them when they go. Easy for DIY so piece of **** for any mechanic. Gasket is cheap and they seem to be weaker around the 250k mark so you could change it as you would a timing belt. Or you could wait for it pop.
My point was that on some engines the required maintanence at high mileage is reasonable and on others it is not. 
Some people own a new motor for 5 years and sell on at under 200k km. If the engine does not stray from its service schedule during that time then they would consider it reliable. 
We are talking about the second hand market for defenders where km can be HIGH. Based on my experience I would still buy a 300-400k TDI engine and be confident that it has another cheap and cheerful 200k left in it. Would I be as confident with a 400k TDV6/puma engine? Less is known so not so sure.
To add something else to the mix when considering prices. The older defenders have less restrictions when it comes to engine conversions.  I think the older ones will be highly sought after when the market sees the potential in rebuild/restore.