In theory, you might be correct (and we'd all like to believe so), but it doesn't mean that a lower cost product will not give you the sound signature you like. I don't wanna detract from the purpose of your thread, but I just don't feel that it is sound logic to pursue the course you are looking at. There are many people on the boards here who prefer a cheaper earphone in comparison to the IE8s I have; and I myself don't like another IEM that is significantly more expensive than the ones I currently use albeit the fact that they are technically better. If the lower cost product gives you the sound signature you life, you end up with savings and that could go into paying for something else, e.g. bills. I have no experience with the Porta Pros and PX100s. I just don't agree with the logic that because something is more expensive, they will be better. No offence by the way