Uh, no, you are misreading that. The conversion kit is $3K. If you don't supply your own T56, that will cost you ANOTHER $3K.
That's the point - a heck of a lot of money for a 6th speed you'll probably never use.
I'm not sure why everyone has to assume if you get a 6 speed transmission that you must be trying to top it out everywhere. The whole reason for this transmission is because like what elf said, it has much better 1-3rd gearing. The factory gearing on the kappas is great when you dont make much power, but as you start to make high power, it wraps through the gears a little too quickly making you have to shift more frequently on the stock aisin ar5. That being said, the more you shift, the less time you have your foot to the ground making the power. The 6 speed transmission is what solves that problem by having longer gears, alongside of being an overall stronger transmission. The actual 6th gear is just a bonus for an extra overdrive when cruising around 80 mph.
I'm not sure why some people thing that I'd be interested in the 6 speed transmission just because I want to top it out. The Aisin ar5 is plenty capable to be able to get you to high speeds! I've done 167mph in 5th gear and was only at 5700 ish rpm, so plenty more room at a 7000rpm redline. So no, not wanting the 6 speed for better top speed, I'm wanting it for the sake of the longer gears down low. Our engine make a lot of torque, I just want to use more of it on acceleration.