Hi there,
My 750 Paso came with a two into one from Star Twin, a company that resides in the Netherlands. It works AOK and it sounds great!
Wouldn't know what price it was, it's kind of a one-off so You'll have to ask them for the price on it. Quality is great, as could be expected from the guys that are supposed to have developed the swinger on the MHE. Or so the story goes...
My bike is running this exhaust with a K&N filter which makes the carburetion leaner, so I'll have to have the carburetion sorted this summer to gain any power. As it is now, it runs like a scolded cat between 3.500 and 7500 rpm. Below and above that it's not great, as was to be expected as carburetion is already lean on Weber-equipped Pasos.
In general, ALL modifications made to an engine, exhaust or filter-wise, will have to be followed by modifying carburetion to gain any power. There are very few bikes that improve by just changing the exhaust or filter. In exchange, modifying exhaust will have little effect without changing the filtering -read airflow- and vice versa.
Check StarTwin out on;
http://www.startwin.com
Jilles.