The 2009 Undergraduate Student dues are only $23 (without a subscription to C&EN), or $44 (with the subscription). You can see C&EN magazines in the offices of most chemistry faculty (and some excerpts on Beth Abdella's bulletin board).
From the ACS website:
"Members receive discounts on a number of ACS professional products and services including meetings registration, courses, and books.
Members can also take advantage of a broad array of ACS group benefits through Affinity Programs that include renters' insurance, travel programs, financial services and discounts from FedEx Kinko's."
If you are planning on graduate school in chemistry, you continue to get discounted dues for the duration of your graduate program.