I guess doing it in polyresin was their only choice of material. Seems odd as they could have probably pulled it off much cheaper in plastic.
Manufacturing in resin is cheaper than plastic by an order of magnitudes.
Steel molds required to manufacture plastic can cost upwards of $40,000. To tool up a newly designed 1/6 scale body, would probably run you $50-60,000 just in tooling costs.
Making silicon molds for resin statues is maybe $60 in costs.
Molding something as huge as Drogon in plastic would require huge steel molds and would be incredibly expensive.
Having said all that, I have no earthly explanation as to why this statue is $1,400 except for the theory that, as mentioned above, perhaps threezero is baking overseas shipping cost into the price, which might account for $200-$300. I think partly what's going on is that even if they priced it reasonably at their true costs, maybe at $800 or so ... they still wouldn't sell enough to make their money back. So they just decided to price it astronomically high so just the die-hards buy it, and threezero will do less work for the same amount of money.
Would you rather make 10,000 hamburgers for $10 each or make 10 hamburgers for $10,000 each?