Narita/Haneda transfer question

What's best way to transfer between Narita (international arrivals) and Haneda (for Hokkaido Asahikawa) ?
How much time should we allow and how much would it cost ? We will have luggage so would prefer least effort alternative, thank you.
PS Would need to do trip in reverse when we leave Hokkaido, so presume same route only in reverse ?

What's best way to transfer between Narita (international arrivals) and Haneda (for Hokkaido Asahikawa) ?

The direct bus:
http://www.japan-guide.com/e/e2430.html?aFROM=2027_2430

How much time should we allow and how much would it cost ?

Cost is explained above. As for time, I recommend to plan a buffer for eventual delays (arrival of international flight, passing immigration and customs). I recommend to calculate at least four hours between a Narita arrival and a Haneda departure.

Would need to do trip in reverse when we leave Hokkaido, so presume same route only in reverse ?

It is one option. Alternatively, you could fly from a different airport in Hokkaido back to Haneda. Furthermore, there are direct flights between Narita and Sapporo's Shin-Chitose Airport.

We plan driving and car rental either from Asahikawa (MUST fly from Haneda) or Chitose airport (can fly from Narita). Could you tell the toll fee from Chitose airport to Furano (nearest exit) ?

Could you tell the toll fee from Chitose airport to Furano (nearest exit) ?

3500 yen from Chitose to Takikawa. But it is also possible to do it toll-free (via Hidaka), although it will be more time-consuming.

Great, you've answered my question--for 3 of us, it's cheaper and easier to fly to Chitose direct from Narita and then hire a car to drive to Furano, Asahikawa, Sounkyo etc instead of Narita/Haneda/ Asahikawa.
Re the toll of 3500, I presume there is a simple formula to figure out the distance on the expressway once you know the toll, do you know it ?
Thank you for all your help.

I presume there is a simple formula to figure out the distance on the expressway once you know the toll, do you know it ?

I don't think there is a simple formula. I always use the following website to look up expressway tolls:
http://www.driveplaza.com/dp/SearchTop

I tried your driveplaza website and it works, yipee.