The Imperial Palace Hotel is having a good sale for 50% off rooms from 9/5-9/8.
Input dates of 9/5 to 9/8, click "view all promos", select "Sept Internal"
If you stay from 9/5 to 9/8 total cost of the room(classic type) after taxes is $48.72
Imperial Palace Hotel Review(Tripadvisor)
HawaiianAir.com currently has flights for $478.19 roundtrip after tax from HNL to LAS.
Hotwire.com currently has a US Airways flight for $451 roundtrip after tax from HNL to LAS