I looked up Hachioji to Nagoya and it is 7580 yen. Then you pay 400 (well 430 with the new tax.... hmmm... added a few yen there, eh?) for Hachioji to Takaido (Setagaya-ku).

My rule of thumb is Nerima IC to Nagano IC, which is 200 km and about 4000 yen but I just checked driveplaza.com and it is now 5,060 yen on Monday morning at 07:30. I swear that I paid in the 3000s for this route a few years ago maybe on a weekend or holiday day.

I am not sure if they took away the weekend discounts after Jan 1, 2012. They certainly took away all night discounts on the Shuto when they put in distance pricing.

p.s. I calculated Tokyo starting at the beginning of Tomei Expressway to the first exit near Kitakyushu and it is 20,000 yen and 1000 km. So $20 per 100 km is a good guideline. Should be able to do that in about 7 hours starting at around midnight. 11 hours according to the calculator.