Well, a Russian millionaire did try to buy Canton island from Kiribati a few years ago for $350 million. For a country with 110k people where only like 20 live in that island group, you can probably overwhelm them with money on a long term lease deal. Now, it does not make sense to do this in the next 10 years when PLA would not have the ability to defend such a base. But 15 years from now when they have 6 carrier groups and maybe 4 Type 076s? Putting them all around first/second island chain doesn't make sense after a while.
I don't agree that you necessarily need a defensible foothold all the way out from first chain to second chain. The presence of 2 carrier groups in that area along with J-20/UCAV/H-20 base is a huge deterrence. It will take many years to build up the infrastructure, but they do have the time to do this. There are quite a few islands in that island group where they can develop and build the infrastructure. Of course, they need to put a lot of effort in to help the people of Kiribati in order to build that type of relationship. Kiribati is very far from Australia. Australia does not have the same influence there as it does with Solomon Island or Fiji.
15 years from now, those 6 CSGs and 4 076s will probably be needed for the PLA just to wage a meaningful high intensity conflict within and up to the second island chain.
Heck, in 15 years, if they only have 6 CSGs in the fleet that would be somewhat alarming.
As for having a defensible foothold to make the islands a viable threat -- no, I'm saying that one needs a defensible foothold all the way from the first/second island chains
and the destruction of the bulk of the US western pacific air and naval forces, for those pacific islands to be a viable threat or deterrence against Hawaii and/or CONTUS.
Relatively isolated island bases during wartime not only need consistent resupply to function, they also need extensive overlapping multi-domain supporting defenses and mobile naval forces (i.e.: CSGs) to survive strikes from the enemy.
If the PLA foolishly deploys two CSGs and a large air base's worth of J-20s, H-20s and UCAVs to Kiribati without having first defeated the bulk of the US air-naval forces in westpac,
and without having successfully defeated and taken islands in the first island chain and second island chain including Guam (to enable a robust resupply and logistics chain to supply somewhere as deep in the pacific as Kiribati), then the US will simply be able to concentrate its air-naval-missile forces and defeat whatever forward deployed CSGs and land based air assets in a saturation attack in detail in a multi-axis manner in conjunction with forces in Australia.
PLA forces deployed there at the outset of a conflict would simply be a sacrificial speedbump that the US could easily sweep aside simply by virtue of the lack of large scale supporting PLA forces in the area and the inability of resupply -- i.e.: the tyranny of distance.
At most, such a forward deployed force would be a bit of an irritant to the US and Australia during peacetime, but they would be massively vulnerable and non-survivable during even the early stages of wartime.
I would agree with you if they had, say, at least 20 CSGs. Assuming 2/3 being at a state of high readiness (1/3 in maintenance, overhaul or workup), during high tension could perhaps forward deploy 4-5 of them to around the deep pacific island bases like Kiribati, while having 10 CSGs in the first and second island chain, to be able to try and rapidly sweep aside US forces in the first and second island chains, to try and rapidly reinforce and resupply those forward locations and the forward deployed 4-5 CSGs that would be immensely vulnerable to US strikes from Hawaii, CONTUS, Australia, and extensive submarines.
But even 20 operational high end CSGs may not be enough -- perhaps 25 may be necessary to overcome the tyranny of distance and the demands of speed for such a mission.
And it goes without saying a large number of SSNs and H-20s would be required as well to enable it to be successful.
Perhaps even approaching a triple digit high end competitive SSN fleet count.