The estimate for cost of electronics is ludicrous. It is a micro controller, a relay, and a PSU. I can build that for $5 at low quantity. PID controllers cost $30 since you pay for low quantity and design. You can build ones from a $1 micro controller, or for even less in analog. Plus you do not need a pid. It makes no sense in that context. It is a thermostat.
They cost what they cost due to product differentiation and similar.
They cost what they cost due to product differentiation and similar.