The Star Inn is an interesting old pub in a lovely little village. The current manager/owner has clearly done a lot of work to keep it alive and there were plenty of locals there. COVID-19 restrictions were in place but it seemed to work pretty well and wasn't too much of a distraction.
The pub was serving pizza for evening meals (in pizza boxes) as many are during COVID-19 times. The pizzas were massive and very nice but we would have enjoyed a more varied menu. If you don't want to drive there are no other options in the village.
Our room was a ground floor annex (possibly originally some sort of out house) which had been redecorated in an effort to smarten it up. This worked to a degree but it was let down but a slightly musty/damp smell, cold tiled floor and cheap uncomfortable beds.
We paid £75 for one night room only in a twin room. COVID-19 changes meant we had to strip the beds before leaving. Although St Erth is a good position for exploring Cornwall, we felt the price was high for what it got you.