The mould for a lunchbox would be anywhere between $15,000 to $30,000(Depending on the complexity of the mould). I'd estimate that if HT confirmed they would make The Bat in 1/6 there would be little or no change from $3,000,000 for the moulds alone(Could cost a lot more). Never mind the plastic for the panels, the metal understructure, plus painting, assembly and lighting, etc. Then you have the packaging, shipping, importation costs,
It's unlikely they could bring a 1/6 scale Bat in under $1000, but lets say they decided $1500 was the most the market could bear for such a product, and they would have to sell a minimum of 2000 of them just to break even. As general business success would be a yield of $3 profit on every $1 spent, they would have to sell at least 8000 of them for it to be profitable.
And if my "picking numbers out of thin air" $3,000,000 cost was wrong(And let's say it cost $6,000,000 for the moulding), then the numbers would have to be increased again.
Injection moulding is not cheap, lol.