$99 would still be a reasonable price for the standalone upgrade kit.
The only problem is that it sounds like the standalone upgrade kit for the 250GB Xbox will cost less than that upgrade kit for the current 40 million consoles in circulation.
No Kinect port supposedly means separate power source and different connection (I'm assuming USB although it may splice into the custom AV port). A small AC adapter shouldn't add more than $10 to the retail price, but a custom cable, assuming it does not connect via standard USB port, could be a "$40" cable like the custom MS HDMI cables.
This is all just hypothetical though.
But I absolutely cannot see MS charging more than $400 for the 250GB/Kinect bundle.
How much they want to charge for the original 360 upgrade kit will have a pretty big effect on just how many early adopters there will be.
$189 = crash and burn
$149 = moderate/tentative adoption rate
$99 = reasonable enough to warrant purchase for most with even a casual interest
Anything approaching $59 and a lot of users will buy the kit even if they have minimal interest in the initial games.
