Looking at e.g. Ebay and Auto Trader it seems that TD5s in good condition, particularly CSW models in near original condition, are getting quite collectible these days and high prices are being demanded. If you're on a budget, then you might want to hold out for one that is a bit less than mint condition cosmetically but which has a solid chassis and sound engine, which may be a bit cheaper. If you manage to get a post 2002 one it might be better they'd ironed out a lot of the teething troubles with the engine by that point.