Hello,
I search high precision (accuracy +-0,1C or better) temperature to voltage or temperature to 1wire digital converter with price max 1$.
I find LMT70 but rel price on mouser is 2$ and china distributor does not offer this component.
Do you advise a suitable component?
Don't compare apples and oranges.
You forgot to calculate the ADC and the VoltageRef:
For your cost calculation:
* temp_to_voltage + ADC + voltage reference
* or digital one wire
You may say any microcontroller has built in ADC and built in reference, thus no additional cost.
But many built in ADCs as well as built in Refs don't come with the accuracy you need.