UK minimum wage takes into account the current supply of labor and many layers of politics / economic theory. This is not comparable to the cost of labor wrt supply in ancient Maori culture.

And disregarding the fundamental error in comparison, the currency needs to be converted to the present Easter Island conversion rate -- does that even exist?

Additionally, total cost is probably not the bottleneck. These were allegedly hunter gatherer's, so TIME was more precious than cost because current theory is hunter/gatherer's didn't have spare time to spend on statues until agriculture.