Answering some questions.
Will there be a 3" version, I would assume no. Corsa specifically makes the exhausts to work with a factory emissions system and tuned for perfect sound and no drone. That being said a 3" would not be beneficial in factory form.
As for sound check Youtube.
Here is my car being tested by the techs at Corsa, They made about 4 revisions to the resonance chambers and mufflers so they could eliminate the drone in the driver compartment.
People scoffing at the price.
You have to realize that Corsa has these made in house and your average welder is paid $20-30 an hour. These exhausts are hand welded. Muffler canisters made from scratch. They also are not like most mufflers which are just crammed with fiberglass. It is a little bit heavier than a stock exhaust system.