Maui-Cheapest Diving Accomidation?

Soon will be in Maui, probably arriving ~April 30th and leaving hopefully no earlier than a month. I am interested in hitting as many dives as possible, most likely shore dives because I am inbetween work and trying to budget. I have all my own equipment, got AOW cert'd several years ago and recently done half dozen dives here in the puget sound. My time frame is I would think at least a month, mabey more depending on how costs go.

I am a traveling solo from the PNW around Seattle. Been diving around here and recently opportunity arrived to goto maui with a friend(non-diver) and get free room for a week. The million dollar question is what to do after that? The most likely suspects are hostels, but has anyone had success hooking up with divers there? I think I will do another thread for a buddy, but I am wondering here what people think is the cheapest way to stay?

I have also heard that people will let you tent out their backyards for nothing, like 50 bucks a month. I have spent the night sleeping under a bridge across from big ben, so I'm not to big on creature comforts.

Also another biggie is transportation, what may be my best bet there? The best car rental deals I can find are $150 a week, would it possibly be cheaper to buy a beater on the island and sell it later?

Thanks,
Zach

BTW does anyone have a take on Maui hostels, I have been reading guest reviews and they do not seem to be too positive. On the otherhand oahu hostels seemed to have a better track record with backpackers. Maui had quite a few 1-no star ratings and really bad experiences relating to the service and hostel workers.

Don't know about cheap accommodations but here is an excellent list of Maui shore dives. It has great descriptions and directions.

http://www.shorediving.com/Earth/Hawaii/Maui/