Have to agree with Dolphinboy...
I have had stacks of Land Rovers, from early classics, LSE, softdash, Discoveries from early petrols, a 6.5gmcV8 Diesel to later ones, but I'd never even think of buying a P38, had several mates with them and they seem to spend longer in the garage than on the road...
So it seems that perception is related to personal experience as there are folk on here with very reliable P38's...
Bought my £80,000 Range Rover Vogue back in the spring for about 5% of it's original price, it has been as reliable as any other green oval I've owned, yes it's had issues but if you are fairly good with spanners and buy an IID diagnostic tool or something similar then they are just as easy to work on as any other, can't say I've thought parts are pricey either... I've changed a few bushes, fitted genuine parts and they are about £30 a pop... fitted new front airbags, which come with the shock as well and it was less than £500 for OEM Delphi ones, that last 12 years (you can get pattern ones for half that if you want) A set of front discs, pads, and wear sensor is less than £70.... There are that many being broken that second hand parts are cheap and plentiful...
I expected problems with mine at the price I paid, but I have to say it has been OK, most of the issues have been from poor maintenance by a previous owner or me drowning it in a 4ft deep river!!! you can't blame it for that...
If your going to buy one and pay someone else for it's upkeep then you will need a large wallet, garages see you coming and think if you own one you are loaded and price accordingly... but they are getting cheaper all the time...