Im not too sure about the property taxes part as Im pretty sure my taxes are higher than that. As far as real estate is concerned, the prices vary depending on the island you are on. I would say that most of the commerce is on Oahu however. Not to mention the majority of the cigar scene! hehe.
In addition to the island that you want to buy on, also the part of the island matters too. On oahu, the general rule of thumb is the further from honolulu the lower the prices. The trade off is the traffic you have to drive in to get to town if your job is there. As with anywhere else, if children are involved then the schools they will go to will impact where you want to live as well. If you get an idea of where you have narrowed your choices, I would be happy to give you thoughts on those areas such as if the schools are good or not, etc.
The thing that catches you a lot in hawaii is our cost of living. As a general rule of thumb you will probably take a pay cut for most jobs here compared to the mainland plus have higher cost of living. Makes it really hard unless you have a lot of coin. Most people make it here by leaning on family. People who move from the mainland dont have that luxury and it can be tough. We always recruit teachers from the mainland (Many from PA and NY). They will stay a few years and then bail when they realize its too expensive to raise a family (no family to lean on). We have the highest electricity rates in the nation, highest gasoline prices, etc, etc. Some places that have good prices on houses are in very hot areas and require ACs running all the time. I have friends whose electricity bill is 600.00 a month. OTOH I live on a mountain where it is much cooler and dont need to use my AC very much. We are pretty efficient with our electricity use (solar water heater, hang dry clothes, etc) and my bill is around 200.00 a month for a family of 4. Just put in a PV system so that will cut down my bill big time once I pay off the upfront costs.
Nursing: If your wife has experience, then it could be easier to land a job. If not and she is a recent graduate, good luck!!! Most of the nurses who graduate from our local colleges cant find jobs and have to move to the mainland to get experience before coming back home. I had a friend whose wife had 15+ years experience of nursing on the mainland and was snapped up pretty quick with a base pay of 75K and probably would make over 100K with the expected OT.
I cant say much about the job you are in since I dont know much about that area.
Lots of hard things about living here. However, we do have great weather, great people, clean air, lots of outdoor activities and a slower pace of life even on Oahu. I guess it boils down to what you value.