I'm having fairly good luck with the Specialized Dolce saddle for rides up to 50 miles or so. Haven't gone farther since I got it. I know what you mean about no leather, as I'm a vegan and do my best to avoid leather, wool, etc; sometimes it's hard to find non-leather items, especially shoes, but under $50 I doubt that any saddle is made of leather.

I found the Terry Liberator to be like riding on a 2x4. It was awful. I've got a Selle SMP TRK (http://cgi.ebay.com/SELLE-SMP-TRK-La...QQcmdZViewItem) I'd be happy to send you if you want to try it, but (like others on TE found) it was too wide through the nose for me.