ESP8266 Community Forum

For the temp sensor if you are ok with soldering then you can put them together very cheaply using components directly rather than all those break out boards.

https://www.thingiverse.com/thing:2166068 shows a box I use to package my temp sensors in. I use a mix of usb powered and mains powered units.

For the mains powered I use
ESP-12F
DSB18B20 sensor (to-92)
HLK-PM03 AC mains 3.3V power module
wire fuse for protection
3 resistors plus decoupling capacitor
Total cost < UKP 4

Note that I remotely mount ds18b20. Locally mounted will normally mean it gets heated above ambient. I find if it is on a short stub of > 3cm then you get good results.

Raginglynx wrote:Are those boards the most pricy option for me instead of the ESP01S?

Wemos D1 Minis (or clones) cost less than 3$ and since they have a regulator on board, you don't need the AMS1117 board from your list, so it's actually cheaper than the components you posted.

Then I also want to build 20-40 230v relays too based on the ESP8266 - but that's another thread :D

I'm with philbowles on this one: don't mess with mains voltage, buy something that works and is safe.