Please note! Asian supermarkets tend to have jackfruit, but this isn't possible for many people, so I won't go too much into this. But if you have a store near you, it's worth a check!
The best ever that I've seen is Aldi for £1.09. But Aldi seem to vary their stock frequently, so this is more of a bonus *look out for it* than a definite find. The brand seen was this Sun Pride one: