An LNG terminal wouldn't help with cost (it would probably increase it a bit, if anything, as the cost of building it would have to be paid back). It's desirable from an energy _security_ perspective; as it is we are very dependent on a pipeline to Britain.
Yeah, even though I voted (happily) for the Greens, I was very disappointed in them not building an LNG terminal, purely for energy security reasons. I'd be super happy if it never got used, but it's a cost worth paying just in case.
Actually it should help with both, because a on-island terminal would also provide LNG storage capacity which would buffer short-term price fluctuations. We have zero such storage.
Again, our poor decision making around national infrastructure is on our governments. They left have left us completely exposed to international markets.