Remote Power On

I have been trying to figure out a cheaper alternative to having to pay $369
to purchase a Beeper Box to turn the engine heater on in my hanger from a
remote location an hour or two before I fly. Before I try and re-invent the
wheel, does anyone know of a product on the market that could do the same
thing without the fantastic price tag. If I don't find it anywhere.... my
garage will offer all the inspiration I need to rig one myself.

....Robbie.