i think it ended up costing me about $25-$35 total. i bought an installation kit for it, but only used some of the parts, because i wasn't crazy about the fitment.

here's a how-to:
http://www.bseries.net/html/garage/s2kantenna.php

i ended up not using that pvc pipe. instead i used this metal piece that's part of the stock antenna, that fits under the fender. fits much better, imo.