Earlier quoted context omitted.
Cheaply btw. Pumping sand is not hard. And, they're doing it on existing reef structures. The sand only lasts because there is an anchor there. This is not primarily military budget, any more than the US army corps of construction is military budget when it builds dams and Levees in the USA mainland (which btw, it does, a lot) Military budget is materiel. Sand, even runways, is not Materiel.
The only purpose for building those islands out is militarily. If it’s not coming out of the PLAN budget directly, I would be very surprised.
So yes, there is a war war not jaw jaw aspect to building the islands, but the budgetary impact? low. Until they fund bulding the aircraft carriers, and stealth UAVs.