Just spent a night at Mathew's. Eco-friendly paradise for backpackers. The place have a house with a few rooms and some cabins outside kind of "gazebos". Water is collected from rain and power from solar panels, so do not expect all the comfort of a "city" place like AC. It is surrounded by nature which comes with expected things like bugs, a bit hard to find, etc.
Note that this place is kinda hostel, meaning shared bathrooms (two for the house and the outside cabins as far as I could see). They were clean when we need them, though. We didn't get hot water but you don't really need it in Hawaii, right? According to some reviews you need to wait a while until it comes warm.
We got breakfast which we weren't expecting since the price of the room is quite ok. The breakfast is not on site, though so you need to drive to get to the store where you can claim it. Only a couple of issues: 1) the smell in the room (#2) kind of moist like when a closed space hasn't been ventilated for a while, and 2) inside the house you can hear every time someone moves or walks around.
We arrived late afternoon and left early and felt that in general it was a pretty good deal.