Personally at £2k I think it needs to be a very good one or at least of had an engine, either re-linered or at least properly pressure tested and rebuilt.
If you can do your own spanner work you can do the engine for £1000 to £1500 if not prob at least another £800 on top maybe more.
I take the line that when buying if this work is not already been done then it soon will be, this way you won't get such a shock when 500 miles up the road you are facing it!! So you need to budget this into the value of the car. Personally I bought one with this in mind guessing from the way the seller was that he had something to hide but knowing that it was cheap enough to put an engine in and still have a cheap but good RR, 2 months later I faced up to it that engine it needed after his suspected gunk in the engine gave up!! But like I said bought with this in mind so I was not bothered, now I have a known good engine that I did myself and so trust the car with no worries, could not do this before!!
I reckon the best way is just buy one that someone has spent a lot of time generally sorting then the engine has gone the often they loose heart and bail out, plenty on ebay like it, there is a good one on at the moment from another landyzone member, his post is here on one of the 1st 2 pages, I feel really sorry for him but his car is here
2000 LAND ROVER RANGE ROVER VOGUE AUTO BLUE on eBay (end time 17-Jul-11 23:49:58 BST) if I had the time I would jump straight in for it as you could end up with a very nice well sorted car, not necessarily much cheaper than buying a complete on the road car but it would be a known engine car for the same money at the end which I think counts a lot.
Do a search on here for 4.6 overheating or similar, if the results don't put you off just get out there and buy the best you can find plenty to choose from!!
Also oike already posted search for buying advice as well plenty of other threads, I'm on my second p38 and will buy another when this one is driven into the ground no problem!!
Hope that helps!!
Steve