You're quoting a Robot rule (<RXX>), so that means it applies pretty much only to the robot.
The OI isn't exactly considered part of the robot ;-).
Also, that rule is for non-custom electronics on the robot. Custom electronics are limited at $200 total, $100 max for a single part/sensor.
I'd go and find the ruling on that, but I'm supposed to be in school in about half an hour
. If no one else can find the exact rules on this by mid-morning, I'll find them.