Defrost problem with Hotpoint FF200E

Hi, I have found a post which lists a modification to my fridge freezer (evap unit ices up like the north pole), which involves fitting a new defrost heater, gutter heater and link harness. This is straightforward enough, but what puzzles me are the prices quoted for the parts. The defrost heater kit is around 46UKP, the gutter heater is around 15UKP, but the wiring harness that joins the new gutter heater into the kit is listed at anything from 65 UKP upwards, for what seems to be a couple of wires and plugs. Am I missing something and does the link harness come with the rest of the bits, or is it a rip off price because you can’t do the mod without it?
The part numbers listed for the mod are:
DEFROST HEATER KIT – C00259475
GUTTER HEATER ASSY- C00140585
LINK HARNESS ASSY – C00141294

Regards
John D