In some cases we have learned of more aggressive prices in the market, and we have used that. When available, the size is included.
Larger sensors offer higher resolution.
Very few support greyscale. If available, we note the greyscale option as sizes will be smaller for those who are doing black and white publishing. Future cameras are likely to support higher bit depths like scanners already do. We report all resolution available for those who sometimes only need the lower resolution, as this option will allow more shots in a session. Equivalent film speed.