The tournament only got confirmed on August 16, venues were officially confirmed almost a week later, matches only went on sale in September, far from large lead in times for selling, especially kicking off in Townsville when the Cowboys last game at home was August 17.
It doesn't help either that the Kangaroos have only played once in Australia since the end of the 2017 RLWC (2019 in Wollongong) and then the two teams taking part in the match have been based out of Airlie Beach (270km north of Townsville) and Redcliffe (1300km south of Townsville) for the lead up.
Eden Park, Melbourne and the Final are on track for better crowds than Townsville. It is likely all these matches will get a boost off the back of the clash kicking off, especially if Australia can play terribly and an understrength Samoan team can over perform and be competitive.
Anyway here is how QCB Stadium is selling so far. Green is pretty much sold out (or down to single seats), yellow is around 90% occupied. Western grandstand is a real unknown, if majority of corporate has been allocated it will potentially take a 14K crowd to 17-18K.