Just to be sure you're buying where it sounds like you want to buy, Waikoloa is on the Big Island, not Oahu. Waikoloa is a great resort, but again I'd hate to see you buy there only to think this would get you home week access on Oahu.
If Waikoloa is where you want your ownership: As an owner at Waikoloa, my $0.02 is that the Waikoloa maintenance fees coupled with how easy it is to reserve there on club points just about anytime you want, make buying there less than attractive. You may do much better--particularly over the long haul and years of maintenance fees--to purchase in Las Vegas and then just reserve Waikoloa when you want to go there. Again, with the exception of Christmas/New Year's holiday weeks, reserving @ Waikoloa is usually very easy.
If Oahu is where you want your ownership: HHV Lagoon Tower is our favorite location there, but as an example is NOT so easy to reserve using club points. In the case of buying there to ensure you have good access there, I'd say the maintenance fees would be worth it to ensure you get there at the times you want to go (for the reason of the very limited access during club season).
This is certainly not to discourage you from buying @ Waikoloa if that's where you really want to be able to go, whenever you want, without the booking fees, etc., but rather just to suggest an alternative that might still get you everything you want at much lower cost.
Hope this helps.
