What are you overlooking?
Well for a start, good luck finding stock of the Titan Composite system.
Second, you have not allowed for freight.
Third, you have not allowed for the tax and duty you will be paying when the exhaust arrives.
Its not like importing a Power FC, the exhaust box is massive and you will more than likely need a customs broker.
How exactly is the above MUCH cheaper than anywhere here, when a quick look through the trader forum reveals you can have a new Kakimoto Regu 06&R cat back for $895, and Stainless JJR Front Pipes with local warranty for $299?