Velo is the company that makes most of those cheap saddles. Look underneath your Nashbar saddle and see if it says "Velo".

I recently went through the same process. Years ago I bought a cheap Nashbar saddle to put on an old townie bike. It turned out to be the most comfortable seat I've ever owned and I started using it for touring. After 10,000+ miles it really needed to be replaced.

So I did a "Saved Search" on eBay. Every day I would be alerted of all the Velo saddles listed that day. It took many months but I finally found the exact replacement. Different brand name, but the same exact saddle.