Best Sensor's for someone who is new to home automation (I am in US.)

[ErnieG (Ernie)]

The link below has one community member’s review of three popular sensors.

Cheapest / Best Motion Sensors & Door open/close? (2016)

What is everyone using for cheap/good motion sensors? I have a bit of everything, and I like the ST ones but they are way too spendy. Monoprice ones seem to have gone up, and I can’t find any of the PEQ ones anymore. What are people using for them? Also, suggestions on good cheap open/close sensors, they seem to be more expensive than they use to be.