Originally Posted by sydney
You specifically need shimano triple 8 speed STI shifters in rx-100, 105 or RSX. Your only option is to find a good used set,as they are out of print. Not real likely for $50. Otherwise, you upgrade to 9 speed with shifters, cassette,and chain.
Maybe get these for Shimano 600's and sell yours. Not $50, but probably under $100 net . . .
http://cgi.ebay.com/ws/eBayISAPI.dll...129215916&rd=1