8 Bit chips tend be anywhere from 1 cent to $3 in volume. 32 bit chips are usually be from $1 to $20. It doesn't tend to be that extreme a part swap - if you'r

8 Bit chips tend be anywhere from 1 cent to $3 in volume. 32 bit chips are usually be from $1 to $20. It doesn't tend to be that extreme a part swap - if you're doing signal processing and UI then you're probably always going to use a 32 bit part. If you're just doing some basic logic with a couple of digital inputs then you're probably always going to use an 8 bit part. You might move 32 bit ARM to 16 bit MSP430 to hit a power budget or similar. Leaving aside processor architecture, the factors that affect cost from most to least (approx) are: Flash size, number of peripherals/features, clock speed, ram size. Basically, sometimes another manufacturer will have a part that meets your feature requirements much cheaper, and then you port the code. The rest of the time, you're just squeezing program space, memory usage and processor usage to reduce the required specs.