According to a post the other day, there currently are no extra Guncon 3's for Time Crisis 4 available in stores to have some two player fun with.
So if your gun breaks, or if you want to play with your friend, then what are you going to do? Well Ripten called up Namco Bandai to find out the story.
"We do not sell replacement Guncon 3's. If the Guncon 3 is defective, then we can provide an RMA exchange where we’ll inspect and repair or replace your Guncon 3."
What about split-screen multiplayer?
But wait! Look! The Guncon 3 will be available online on December 20, 2007 thanks to Ripten's Brian spotting it on PlayAsia. So calm down, and pre-order your guns. When the family comes over for Christmas, you show them how to play.
You can play the split-screen with one Guncon 3 and a controller. If you wish to play two players using two Guncon 3s then you will need another copy of Time Crisis 4.
Is there anything else I can help you with?