Larry, Hawaii land is ridiculously expensive. A median single-family home is $600K although your description might go for "only" $485K in some areas/conditions. A median condo of that size is $300K plus homeowner's fees of $200-$500/month. Of course some neighborhoods are cheaper than others, and good school neighborhoods cost more. Many residents don't care for their homes (there's almost no environmental penalty for neglect) so some areas may discount as much as $100K for poor maintenance. Jumbo mortgage loans don't kick in here until $625K, unlike most Mainland limits of $417K.
Construction is also quite different from Mainland homes. No brick, ever, and stone or lava rock only as accent or very-high-end construction. "Modern" homes have Masonite exterior sheathing over 2x4 wood frames (a small minority with steel frames) and interior drywall. Insulation is the exception, not the rule, as most homes aren't designed for A/C. Windows tend to be single-pane aluminum or vinyl, almost never wood. Jalousies were more common before the 1980s but casement and awning are more popular today. I've only seen double-pane insulated windows on 2010 new construction designed for A/C.
Lot sizes are small and measured in square feet. A "big" lot is 5000 sq ft (1/9th acre). Newer homes tend to be two-story on 3000-4000 sq ft lots.
Many homes (over 35% currently, and all new construction required by law) include solar water heating. That can reduce an electric bill by $100/month. We have more hot water than we can use except for maybe 3-4 overcast/rainy days/year. (Systems have electric backups, which we never use.) Not all homes require A/C. We mostly dress in t-shirts, shorts, & slippers but it's a hassle to put on business attire at home and have to commute without sweating it to death.
Oahu is overbuilt but does not have an excess inventory, so homes only lost 10-20% value over the last couple years. It's expected to remain flat for another five years. For most, renting is the better choice although fearless DIY handymen can rent to learn the various neighborhoods and then scoop up a cheap fixer-upper. It's worked well for us, and Home Depot/Lowes have made the renovation process much easier/cheaper.
Akratic, I agree with you about the location. The islands have a large transient population, especially Oahu's military. We much prefer Hawaii culture to the Mainland and the surfing is excellent. I enjoy Thailand and the rest of southeast Asia more than Latin/South America. Haven't made it to Australia yet but lots of Oz expats make Hawaii their home or their bridge to the Mainland. Most Mainland transplants to Hawaii, and many Hawaii residents, end up returning to the Mainland when their kids go there for college and/or career (it's the grandchildren). Other Mainland transplants may return there to be closer to aging parents.
We didn't originally intend to move to Hawaii, but the Navy made us an unrefuseable offer and we later realized what a great deal it was. We're estranged from our parents/siblings and our kid just started college (NROTC) so we don't have any strong ties to the Mainland, nor will our kid. However many who grew up here and left will return in their late 20s/30s to raise their own kids here, which is the path our kid is most likely to take. (Or not.) The five-hour flights to the Mainland can be a pain, but our kid will be welcome to send the grandkids to us for visits.
For those seriously considering Hawaii, I'd strongly recommend reading HawaiiThreads.com. They get a lot of malihini questions there, and it's amazing what issues pop up at the last possible minute (or after it's too late).