I don't think there are many alternatives. Some are renting thru Turo, with those owners jacking the price through the sky. If you stay in Kailua-Kona for the most part you can probably get by walking and Uber or Lyfting.
Keep checking through Costco, Discount Hawaii Car Rental DHCR.com, up to the day you leave. If you see a car available, reserve it and keep looking. Most experienced Hawaii visitors will reserve a car, sometimes two, as soon as they book their airline tickets. I know we did back in January for a July trip. When it gets closer to your arrival date some of those overbookings will be released and will come available.
Don't cancel your trip, though you will have to figure out transportation from the airport. KCR has a nice pool area and nice grounds. It's right on the ocean, but not swimmable. All lava rock. There is, or used to be a sort of trolley that ran from the town out to Keauhou Shopping center.
Turo is kind of an Airbnb for cars. I have never used it, but it is something you could check out. Good luck
Keep checking through Costco, Discount Hawaii Car Rental DHCR.com, up to the day you leave. If you see a car available, reserve it and keep looking. Most experienced Hawaii visitors will reserve a car, sometimes two, as soon as they book their airline tickets. I know we did back in January for a July trip. When it gets closer to your arrival date some of those overbookings will be released and will come available.
Don't cancel your trip, though you will have to figure out transportation from the airport. KCR has a nice pool area and nice grounds. It's right on the ocean, but not swimmable. All lava rock. There is, or used to be a sort of trolley that ran from the town out to Keauhou Shopping center.
Turo is kind of an Airbnb for cars. I have never used it, but it is something you could check out. Good luck