Cisco does have an add-on for the 1200 Series AP that allows it to use the 5 GHz band as well (802.11a) ... the Cisco Rep here told me they are planning on having a 802.11g module available once the standard for it is finalized this fall (Linksys and everyone else jumped the gun and went off on their own).
With and Cisco (as with everything else) you pay for what you get. IMHO, Cisco is pretty much the best stuff you can get ... we have tried D-Link wireless equipment and learned the hard way why it was cheaper. Lots of DOA stuff, D-Link doesnt support any network running WEP, other incompatibilities, etc.
So ... I would say Cisco is expensive because you are paying for the quality and the guarantee that everything will work the way it supposed to (and if not they are very happy to help, and in my case they even came on site to figure out what was going on).
*shrug* Matt Laski
Sysadmin, Pulsafeeder Inc.