Does anyone own/owned one before?

Specifically the 3.2 Auto?

Only reason I'm asking is that I have been offered one at what I feel is a decent price. Its 'R' reg (98) with 120k.

I've never owned a Jag before, and to me it looks like a ship, but I like the look of it, and wouldn't mind it as a sort of 'weekend' car. All interior/exterior look fine with part service history.

Just want to know if I should go for it or are there any problems that I should look for?

price?

£850

It'll be a money pit.

in what way? unreliable? or running costs?

you're pretty much on xj8 sport money there. dependant on the model and what it's had done might not be bad price.

my husband had an old Jaguar XJ 12 a few years ago as his weekend car, and he loved it. Get one, you only live once, but make sure you have something to catch the oil that will leak out of the engine onto your garage floor

So what are the engines like? Should I be worried with it being on 120k? Is there anything that I should be looking out for?

Any specialist car, especially an old one, is going to be expensive to keep. Just as a guide, try adding up:
Tax
Insurance
Cost of fuel per 100 miles
Price of tyres
Cost of an exhaust

and compare with the costs for your present car.