I got my PIDs for $16 and the thermocouples for $17 from china. Details below. They were so cheap I bought a second one just to monitor the wort temp as it comes out of the mash tun. this way I can monitor the lag in the HERMS. Thermocouple came with a 1/2 inch thread. I used this with a stainless tee and 1/2 inch barbs to hook up to silicone hoses. I have a picture of it all set up, but I can't work out how to attach a pic!
The PID controller switches an SSR relay that switches my electric kettle on and off. I get a lot of disbelief for using my $7.50 BigW kettle for a HERMS but if the coil in the kettle is sized appropriately it works perfectly.
PID PID REX-C100 Temperature Controll
er +max.40A SSR +K Thermocouple
Probe 0-400thermo RTD Pt100 ohm Probe Sensor L 50m
m PT 1/2'' Thread with3 Lead Wire 6.
56ft