Google maps and Shinkansens

I have a trip in November and am looking at Google maps for all the trains – which I have been told is super reliable.

However I was wondering if the pricing that is displayed on there for the Shinkansens is accurate? I was unsure if it takes into account reserved and non reserved seating?
I’m just trying to figure out a rough estimate of how much I should be budgeting for the tickets 😵‍💫

Also, would it be safe for me to just get the tickets on the day I’m going? It’s not a peak time and I don’t want to be restricted by a time frame of when I need to get to and from different places.

Any help would be appreciated thank you! 🫶