Compare it easily to trademarks, you can get things quite cheap owning the same or near the same performance if it doesnt show a well known brand or stamp. It might be made in the same company, but it is sold under different trademarks....

I can tell you that you might probably in the stage where many of us have been or many of us are still into....the search of the holy grail of stones ;-)

We all strife to find that one stone delivering the best we are looking for. In the end i would tell it doesnt exist! Everything is personal preference weather you like a specific type of stone or not. Stones which others like or propose might be the wrong one for you, Stones you like might be wrong for others. The only way to find its is trying out what suits you personally the best.....

The stones you mentioned are all different and in my point of view do not have a cheaper substitute. The only way to get one cheap is to buy an unlabelled version.