[Zatyme]

Also the creation of brand new steel molds are extremely expensive. As while this is baseless assumptions I feel like due to the size Grand Liner might have a similar amount of plastic in it to Generations 2012-ish Metroplex, a figure that former lead designer Aaron Archer theorized cost close to a million dollars to produce the master molds for.

So it's most likely the cost of producing the brand new steel molds and the drastically smaller production run of the kits compared to standard Bandai High Grade kits, alongside the amount of plastic used and the pre-applied paint.