You might be able to pick up the Universal version for a bit cheaper, perhaps via Amazon?? It comes with
Terror in Aisles as a bonus feature.
Here it is on Wow but you'd have to add the VAT on top so might be better finding it elsewhere. They also have the SF disc for around £16 (ex VAT)
https://www.wowhd.co.uk/halloween-2-1981/025192117558