REF200: How can I select a current reference for my designs?

Hello everyone,

I am trying to accurately measure temperature using a 3-wire PT100 RTD, I thought to use a REF200 and the INA326, using the reference circuit from the REF200's datasheet, but I will use 4 sensors and using a REF200 is very expensive Are there cheaper alternatives for the REF200? Or maybe there is another IC that can help me with this purpose but that is very low cost.

I thought that the REF200 would be a good option, but I don't need much precision in the measurements of the RTD signal because I think I have an error in the measured temperature of 0.1°C.
I hope you can help me.

Regards.