If we are going by the precedent of the case Apple is trying to argue from, at least from what the article states, I believe there is definitely a debate to be had. The original case was ruled as such because of chain of supply. The contractors were buying from the concrete supplier, and then selling higher to make up for cost. So the Court ruled it'd be too difficult to figure out how the purchase of the concrete altered pricing of the second company. In this case though, the vendors (app makes) aren't purchasing anything from Apple, they are simply being charged a fee to use their store front, and that fee is being passed directly onto the customer. So while there are similarities in the two cases, I could absolutely see how they could rule against the argument Apple is putting out.