Cheaper to ship furniture or to buy on the islands?

Doesn't matter if block or not. You can have subterranean termites and if purchasing a wood house or mixed construction, it's good to know what you are getting into. You're spending a lot of money on a home and you need to know the total condition.
The home Inspector should be able to advise whether this added inspection and cost will be necessary but it's good to add into a written offer to purchase, in case it's found to be necessary to have one. If it's not, you are not required to have it done.

You'll want to get rid of any nests found in trees near or on the property and have continued vigilance. Good Luck.