One way shinkansen from Nagano to Tokyo

I am hoping to catch the Hokuriku Shinkansen one way from Nagano back into Tokyo in January. (I am catching a bus over to Nagano a week earlier). I read on a forum that the journey should be about 100 minutes and Y8000 and to make an advance reservation.
The fares I am seeing are Y17900 + a basic fare ticket (another cost). Its starting to sound really crazy expensive for a one way trip! Can anyone help me out here? Is it likely to be Y8000 or Y17900++ ?
Thanks

Hi there,
Where are you getting your info? The cost is 8,340yen. If you find a higher price it’s either for the “green car” (first class) or it’s a scam. It’s a little confusing, but there are always two components to Shinkansen tickets. The regular carriage fee and the reserved seating/express fee. In this case they are 4,070yen and 4,270yen respectively.
Unless you are travelling in the intensely busy period of December 28th to January 5th, you probably don’t need to book much in advance, if at all.
Good luck!
Greg

Thanks for your reply Greg. I think I was on the JREast bookings / reservation site. I do want to travel during the busy period (2nd Jan) so I will need to reserve a seat in advance. Can you possibly provide me a link to find this better fare?

Here are some trains from the Hyperdia site on January 2.

http://www.hyperdia.com/en/cgi/search/smartphone/sp/en/hyperdia2.cgi?dep_node=NAGANO&arv_node=TOKYO&via_node01=&via_node02=&via_node03=&year=2020&month=01&day=02&hour=08&minute=15&search_type=departure&search_way=time&transtime=undefined&sort=time&max_route=5&faretype=0&ship=off&lmlimit=null&search_target=route&facility=reserved&sum_target=7

Price is indicated as 8,540 JPY. You can pick up your ticket and make a reservation in all larger JR stations at a ticket terminal (in English) or in a JR Travel Center. Credit card or cash is accepted, no suica or pasmo card in my experience.