50 is the average price for the unit itself. usually (even on ebAY) the control comes harnessless. like my brother said there 7 sensors that need to be wired in the idle air, glass temp, external temp, internal temp, the cross over (for auto temp switch on) and the misc ones that run to the harness. anyways if you can source out the sensors heres the right up for the install. its for an S14 but i assume its similar for the s13.

japanese domestic market » Nissan