TPS and RPM only?

[John Hess]

>>Is there any particular reason that aftermarket wiring harnesses 
cost
so much money. It would seem pretty simple to wire one up?

Yeah,  the materials (particularly the plugs) cost money and the 
technician's time (not normally cheap) must be paid for.  If you can 
do it yourself, maybe you can save the technician's pay;  but, you 
will still have to test it yourself.  Consider the costs/consequences 
of one innocuous mistake.