Have u come across any micro-controller with memory of 256KB (Flash) and 16bit ADC(SAR,8 channel at least) with more than 250 segment LCD driver. I may compromise on LCD but not on ADC.
My requierment is to have that micro in less than 2USD per 10K /annum. Please let me know if u seen one.
No need to search any more, there is no micro with your specifications, at least none anywhere close to your target price.
You can get a 16-bit Sigma-Delta ADC on an ARM7 from Analog Devices but that device has max. 96K Flash, no LCD and costs approx. 3x of what you want. And just for your information, the cost is in the ADC and in the Flash, not in the more powerful CPU that you might not need.