Taxi to Mt Aso crater

I will be heading to Japan in January, and plan to visit Mt Aso while travelling between Kumamoto and Beppu. JR has a number of express trains on this route that stop at Aso Station. However, the buses thatAso run between Aso Station and Asosan Nishi at the crater have no relationship with the JR arrival and departure times, and involve a lot of sitting around at Aso station. I would rather spend this wasted time in Kumamoto.
It seems that the only other option is a taxi. Does anyone know how easy it is to find taxis (both at the station and Asosan Nishi at the crater) and how much they would cost?

Take a taxi from Miyaji ( two stations from Aso ) to the ropeway......about $35. The good folk at the ropeway will call one to come back and collect you. I had to do this a few years back due to not being permitted to go to the regular bus drop on a/c of wind direction and dangerous gas.....never did go back to that restaurant :-)

Thanks for the suggestion RodW.

However, I will be taking a Limited Express Train to save some time - they don't stop at Miyaji, only at Aso Station itself.

One of the busses from Kumamoto stops 1 1/2hr. at the Aso volcano allowing time to get up to the rim and check it out, I think it's around midday.

The Odan expresses stop at Miyaji four times daily.
0947, 1250, 1551, 1852
perfectly spaced to go up the hill and get back for the next one.

Last year, I also went to mt Aso by JR and the waittime for the bus from Aso station to the volcano is 'only' 45 minutes. and yes, there is not much to do around Aso station, the busstation looks like a shed (with a vending machine,lol) but I was not the only one waiting for the bus and had a nice conversation with a Japanese family, a tourist from Norway and a couple of flight attendants from Hong Kong on a day trip, so those 45 minutes flew away and I had a good time,lol

Perhaps you should seriously ask yourself if it is worth going to all that trouble just for a quick peek. Not every Must SEE tourist sight is actually worth seeing depending on tastes, schedules and other parameters. At any rate it doesn't make sense to take a faster train to end up waiting 45 minutes when a slower train bring you to a station with more frequent buses or cabs.

I visited Aso earlier this month and have the bus timetable. Leaves Aso Station 8:57, 9:52, 10:40, 12:20, 13:25, 14:15, 15:20. Leaves the crater 40 minutes after the departure times from Aso Station (i.e. 9:37 etc.).
Don't be put off if it is foggy on the way, the crater itself seems to remain clear.
It does snow up there in the winter time though.
As for taxis, there was always some there whenever I was at the station, but no idea how much they cost.

We're thinking of renting a small car from Kumamoto and seeing Aso area and finishing in Beppu. Anyone able to offer advice on this idea, the route,places to stay etc. please? Is it better to get the car closer to Aso?

Just got back from a terrific 10 days driving holiday in Kyushu and as for Aso crater, I would second Auntie Bertie's advice. We drove and I came away thinking why we even bothered. With a car it was easy and yet it still took time getting up there but at least we can drive to the very top meaning you can avoid the ropeway. When we got there it was raining and very windy + the crater was covered by fog or smoke, anyway we couldn't see anything. Since we can't predict the weather I just thought you should know that you could be going to a lot of trouble and be disappointed. There are lots of other great things to do/see in Kyushu.

Your plan would involve substantial drop charges of the order of 7000 yen. Personally, driving is definitely the way to go as you gain so much time + many sites are realistically only accessible by car. Having said that you should plan your driving trip carefully so you start and end in the same place and avoid the high drop charges. Have a great trip.

Yes, thinking about it, I think we'll look at renting a car from Yufuin and being based there ( if we can find a reasonably priced place - not easy!) - lots to go and see from there even if weather was bad. Anybody know a good budget ryokan?

Thanks for the info RodW. For reasons known only to Japan Rail, the printed timetable does not list Miyaji as a stop, but the hyperdia confirms that it is.

We managed to rent a car through Tocoo at Yufuin and plan to drive to Takachiho etc. over 2 days while based in Yufuin