TPS55289: Power supply IC selection

Part Number: TPS55289

Hi TI team. We are looking for a low cost power supply IC which should cost nearly 1$ -1.2$. Our requirement is 

Input Voltage - 10V - 30V dc (Variable input),     Output Voltage- 12V , 0.1A Dc (Fixed) 

This requirement is for inductive proximity senor application. The yearly required quantity will be 50000Pcs and it will increase as our sales will grow.

Please provide the power supply ics which will be suitable for our application. Also please share the reference designs for our 12v fixed output application. I have tried TI webench power designer but i am getting designs which has transformer which isolates the output and quite confusing for us. Let us know if TI can support on this or else we have to look for other vendors like STM, microchip.