To each his own when it comes to these beasts...
Best advice I can recall is buy at a reasonable price and set some money aside. These are tough, reliable cars with well documented maintenance requirements/known weak points.
I bought my '99 on the back of a thorough once over with a buddy and a short drive. Checked everything worked as it should and haggled a good price.
I only paid $3K in August last year (in Adelaide) but fully expected to spend $$ from day 1.
For the record the day i picked it up I replaced the battery (shot), tyres (shot) and planned my upgrades from there. I expected to have to spend some money on cooling system even though it was ok at the end of winter and sure enough have had to replace the radiator, thermostat, waterpump and hoses.
I wasn't expecting to have the AC compressor fail on me but it did - no huge surprise and popped a new serpentine belt on at the same time.
I dropped the engine oil and replaced the oil and airfilters at first opportunity and have since done all other fluids as preventative maintenance.
Front discs and pads are about to be replaced in the next fortnight.
I fully expect to have to replace some sensors at some point so will be oredering these in to have on hand when the time comes.
Also, I'll be doing an ignition tune up very soon, new plugs, leads, coil, dizzy etc.
When everything else is 100% Tip Top i will do a proper suspension lift and a new exhaust with extractors.
By the time I'm done getting the XJ up to scratch and lightly modified I reckon I'll have about $7k sunk into her (yep more on keeping her going than on buying her!) which is pretty good value i reckon for a comfortable, capable daily driver that can go bush when nature calls!
I guess the appeal in these rigs is that they can be worked on at home (I'm no mechanic btw) and are pretty reliable for the most part, they just need a little love and understanding. Bear in mind that even the last of the updates are getting on now and you WILL spend money and time somewhere along the way
Also I love the fact that i can do an oil and filter change for less than $20 if i buy at the right time (have 2 spare oil filters from promotions now)...much nicer than the $150+ on my other car.
Someone around here put it like this - budget a couple of grand for maintenance/repairs on top of the purchase price and if there's money left after 3 months or so start modding!