Buttery Commissar wrote:It is more expensive due to material and construction.
In an art store this type of brush would be more expensive than a regular brush, but it would not cost quite as much as
GW charge.
Exactly. Brushes are available in a wide range of quality, with better ones obviously costing more. In this case
GW has probably stuck their logo on a high-end brush* instead of their usual lower-end stuff because fine detail brushes are where you get the most return from buying high-end brushes. You could go to your local art store and get a whole set of brushes like this, if you're willing to pay for them.
*
IIRC GW doesn't actually manufacture their own brushes/tools/etc, they just take the same stuff you can get at your local art or hardware store, put a
GW logo on it, and increase the price. It's almost never worth buying stuff like this from
GW because it's literally the same as you can get elsewhere except more expensive. It's just a trap for non-gamers buying gifts and/or kids who don't know any better.