Thanks, I appreciate that.
Here is a cost breakdown.
You can do it less expensively than I did it, mainly where the switches and relays are concerned.
The approximate breakdown is this-
Main (AC) relay $16.34
Relay socket $2.85 (optional)
DC relay $5.52
Perf board $2.20
LED $0.55 (optional)
Power on switch $8.43
Power off switch $11.39
Override switch $8.04
Misc. wiring $2.75
Thermal switches $3.75 (eBay)
Printed housings $????? (self-made)
Peace of mind and convenience- $priceless$
You can definitely use a less expensive main relay.
I opted to use a DPDT high current plug-in version with an integral indicator light.
You can use pretty much any SPDT or SPST-NO relay with the appropriate coil voltage and contact rating.
They are out there at around $7.50 if you look around.
The secondary relay is not that expensive to begin with, but less expensive ones can be had.
As for the switches, remember that I happened to have these laying around from another project, so my cost was actually $0.
You can use any common normally open pushbutton for the on switch, any common normally closed pushbutton for the off switch and any common rocker or toggle switch for the override switch.
As long as their contacts can handle the current and voltage of course.
You can probably get by for less than $10-$12 total for them.
That would bring the cost down to around $38.
I would be willing to create a version of the switch housing that has round holes (or no holes) rather than square ones if anyone needs that.
Then more common (and less expensive) panel-mount switches could be used.