How can they even justify that kind of thing? It's not like plastic is hard to come by. They're just justifying their insane pricing system by claiming they cater to discerning customers in a niche environment. And that somehow gives them the right to go to town on price tags.
GW uses careful market research to determine what customers are willing to pay. Focus groups and polls.
A focus group is usually two people standing around a water cooler in Nottingham.
A poll is a third person walking past with takeout menus, asking "Indian or Thai?".
In all seriousness, it has to be a collective, corporate arrogance. GW has been consistently hiking prices for years.
They used to offer excuses. Price of metal going up. Price of oil (for plastic) going up. New, expanded ranges of more detailed miniatures.
Now, they don't even bother. As long as people keep paying those prices, GW will keep charging them.
When people stop paying those prices, GW will scrap a game and introduce AoS.