what island? i normally spend 2-2.5 months a year on the big island... there is NOTHING that cheap unless you want to stay in some shit area in the middle of Kona... the higher up resorts in my area go from $400-$1200 a night for the normal rooms and private bungalows go for $3,000-$6,000 a night
but I'm sure there are things for $200-$300 in the same area, but you got to pay to play honestly when it comes to hotels there..