Suppose it's like any car - could be good, could be bad. I suppose in theory you're never going to lose
loads on money on it, if it breaks and the scrap man takes it away in 6 months for £100 it's not the
worst financial decision in the history of the world.
I'd imagine the only bad way to own this car is if you end up loving it, then pouring more and more money into, until you see that a trouble-free motor from the Jag equivalent of OOF (The JOF??) could have been had for only a few hundred more. Buy a sorted car for £1000, or get a banger for £250, then spend the next year and £2000 on it, to get it to nearly the same standard of the £1000 one in the first place.
But if you run it until it goes 'pop' you've invested nothing in it other than the initial £250, of which you'd hope you'd get back most of that selling it as a SORN non-runner on the heebay. Not a massive fan of cheaper is better, but in this case, can't see you losing much on it.