Your agent can advise you. The question is, will it be good advice? If you're working with a seller's agent, both legally and ethically the agent should encourage you to offer full price; not very helpful. If you're working with a buyer's agent, the agent has a responsibility to provide you with good market information to help you make a decision. However, even the buyer's agent usually doesn't get paid unless and until there's a deal, so his or her interests (a quick sale) aren't really the same as yours (a good price). In short, ask the agent, but take the answer with a grain of salt.
The truth is that the agent really doesn't know what price you should offer any more than you do. Nobody really knows what the sellers will accept once an offer is placed in front of them. I've seen hard-nosed sellers fold and meekly accept a terrible offer (for them). On the other hand, I've seen very desperate sellers, who were face with foreclosure, hold out beyond reason for a price the believed they should get. Nobody knows for sure what a seller will do. That's why the only way to find out is to make an offer.
Your Hawaii real estate agent can be helpful in providing you with market data, which can be useful in persuading a seller to accept your offer. This frequently includes a list of what similar properties have sold for over the past year. The idea here is that if a house just like the one you want to buy sold for $200,000 last month, the one you're buying should be worth about the same.
The trouble is that if the sellers happen to be asking only $195,000, they will love your argument. On the other hand, if they're asking $250,000, they won't want to hear it.
In addition, markets are always in a state of flux. Conditions change, sometimes swiftly. I can recall back in 1989 when I was selling a home in southern Hawaii and the market suddenly dropped; values almost overnight were 10 to 15 percent less than recent sales would indicate. Smart buyers balked at paying old prices when the market was falling.
On the other hand, I was selling a home in northern California in 1997 when prices suddenly skyrocketed. Again, no one cared what the old price was. Buyers just wanted to lock in a sale at any price before the house became more expensive.
Yes, ask your Hawaii agent about previous sales. But also ask about how the market is doing, and don't rely just on the agent's observations. Check with the local newspaper, which invariably will carry articles lamenting a down market or promoting an upward one. Then act accordingly.