Question on Hyundai servicing

Looking for some advice on getting my car serviced, if possible, as this is somewhat new territory for me.

I just bought a Hyndai Ioniq, and its annual service/MOT is due imminently. Until now I've always just gone to my local Halfords for convenience but a few things here and there have made me question them and the new car has a fully-stamped service history so I'm thinking I should keep that up.

But the service point is recommending a \~£750 5-year service (versus a \~£250 "essentials" service, roughly what I'm used to paying), which doesn't seem at all reasonable to me - and given what it just cost me to change cars I could really do with not spending another £500 if it's not needed.

Would I be stupid to go cheap here? I assume the consequence would be lower resale value due to not keeping fully up with the manufacturer's schedule, but is there more to it? The website is really vague about what the actual difference is between the service levels so it kinda looks like a bit of a rip off to me.

Any insight would be appreciated. Thanks