FREE for the cost of mailing:
a HL (hing lung or something?) made "Kalin" suspension seatpost from a Giant "comfort/recreation" bike; 29.2 diameter, adjustable preload (at bottom) and still seems to work.
Complete with somewhat rusty steel saddle clamp and rubber dust sleeve...will weigh about 1lb, 8oz. when packed up so you can calculate postage based on mailing from 94118.
Pick up in person for free (SF or down peninsula on weekend).