My 91 model Evrude 15HP had the switch that clips to your shirt.I always kept the spare in the button grooves.
Had issues with engine dying for years,thought plugs,wires etc.
One day I checked switch,it was coming&going.
as you said,$80 for a new.
I put a toggle switch from Advance 10 yrs ago,looks a little rusty on the outside,but never failed once.
They also want $80 for the wore out rubber on the twist grip.$160 to make the tiller like new!