Cheap place around north Kyushu

Hey, it's my first time travelling to Japan and I'm currently in Hiroshima, planning to go to Kyushu in 2 days. I have a hotel reserved in Fukuoka for 3 nights but after that the place is reserved and I don't have a place to stay. I've tried searching for a hotel or an apartment around Fukuoka or Nagasaki between 15-21 of November but I can't find any reasonable price.

I'm travelling with my girlfriend and we prefer to stay at a hotel or apartment and with a private bathroom. The reason we need to stay here until the 21st is because we have a flight from Fukuoka to Okinawa that day.

Everything I'm trying to book is over $100 a night and it's pretty sky high. I'm currently at a hostel in Hiroshima and I'm paying 24,000 yen for 3 nights, while I had a pretty decent hotel in Osaka for 4 nights at around 15,000 yen.

I'm really trying to find a comfortable place to stay in at a reasonable price, and it doesn't have to be inside the major cities. But I do need a convenient public transportation to get there and back to Fukuoka.

Thanks in advance!

From the 15th to 21th, that's 6 nights with a weekend in the middle; you are unlikely to find a,y reasonably-priced place with available rooms for all 6 nights. Instead, look for one for just the 15th, then the 16th, etc. Yes, you will pobably need to change hotels, but if they are in the same city it's not too much hassle.