Multi function printers can print, fax, scan, and copy; they are great space and money savers, and are ideal for small offices. They use Inkjet or Laser technology. They offer much greater versatility and are economical when compared to the price of all the individual components put together - the only glitch being that the efficiency with which all these functions are performed, is not at the optimum level. Also compared to other printers they need more warm up time and consume more power.
Inkjet multifunction printers are cheaper, and print in color, but are slow. Laser models are faster but color versions are expensive. Within a fixed price range, Laser multifunction printers are the best bet. They offer additional features like duplex printing, built-in networking capability, and automatic document feeders.
For small office and home uses 8 MB memory would suffice, but for large documents and multi-user purposes, larger memory of 16 MB would be required. Price increases manifold with increase in memory capacity of these printers. Standard resolution of 600x600 dpi would be sufficient for normal purposes. For photo quality, higher resolutions would be required.