I've had a couple of people ask me about this piece, here's what I have said in response.
I don't think that dropping to just one muffler, even a TORs unit, would be beneficial, with two mufflers there is two for the Engine to breath through.
I think that with a larger diameter connection piece and a more open muffler this would work.
The US$80 quote was for a 38mm (1½") O.D. connection piece, having thought this through some more, I went and drew up a 2" O.D. connection piece.
This, with the stock inlet seal and no seal in the muffler, would slide straight into the stock muffler.
All kind of not worth the effort I think.
If you are going to use a more open muffler, get one that slips straight onto the stock header.