It could also be that they priced the 20 piece at a reasonably high margin and the 10 pc was half of that to begin with. Then they experimented and realize that demand is inelastic to price.
From there they just kept stepping the price up and discovering it was the same as the 20 pc and that's the equilibrium we are in today.
From there they just kept stepping the price up and discovering it was the same as the 20 pc and that's the equilibrium we are in today.