If I were single and had the means to swing it, I'd buy. Just keep in mind houses are tiny here, come with no land (in most cases, I mean this literally), and can be in some really shitty neighborhoods. One of our O-4's just got "a great deal" on a condo in Kailua for like $400K. After he moved in, he realized that he's downind from the sewage treatment plant. . . In a "decent" section of Kailua, a 3 bd/2ba, 1500 sqft house runs about $500K and will be 3 or 4 blocks from the beach. Prices go up exponentially as you get closer.
I'm married with two little tax deductions, so there's no way in hell I could have afforded to buy in Kailua when I checked in as a JG, but I know a couple of guys who are doing it now and some O-4's who still own their JO-tour houses.
That said, as a single dude, you'll make like $2300/mo in BAH and another $900 in COLA. If you rent a McMansion on the beach in Lanikai with 3 other guys, you'll have far and away the sweetest pad and you'll be able to bank like $2k a month from just the "Hawaii Pay" (or spend it on booze).
And base housing is awesome here. HUGE houses by Hawaii standards, they're all brand new, and all walking distance from the one of the best surfing and snorkeling beaches on the island.