what is the least expensive, moderate speed (20 - 40 pgs/minute),
color laser printer that is commonly avaiable?

Color printers now have an ISO rating for their cartridges that
determines how long the toners will last.  They also have a system of
determining how long long the consumables last (and therefore cost of
consumable per page can be determined).

Could you look up the various color laser brands and provide breakdown
of cost per page of consumables of the top 20 moderate speed color
laser printers?