Most major semiconductor manufacturers, including Motorola, Philips, Intel, Infineon, among others, sell CAN chips, and the fact that millions of them are used in automobiles guarantees low chip prices.
As a matter of fact, implementing CAN into a new application can be accomplished with less hardware costs and less development time than, for instance, RS232/485 or TCP/IP.
CAN software libraries, even including CANopen or DeviceNet protocol stacks, require a significant lower memory footprint and far less CPU performance than any TCP/IP implementation.