Ok  the first have this big problem for top and bottom pot, but the second one look amazing am really looking forward to have fews of them ... yes maybe 200 €  is quite expensive even because 1 sensor is not enough I need min 4/6 sensors, thanks again , I will wait for them !

We made own sensors, measuring the conductivity of the soil. the results where quite bad  because the pot can be dry on the top but the bottom part is still wet (https://core-electronics.com.au/sparkfun-soil-moisture-sensor.html). There are senors with a humidity sensor packed in a air stone (https://core-electronics.com.au/soil-temperature-moisture-sensor-sht10.html). This shows quite nice results but the price for the sensor only will end over 200€ for the retail. To expensive. Actually we are looking for a reliable soil sensor....