I have not found ebay that helpful. First, the plants are occasionally misidentified and secondly, there's not usually that many Sans pictured there at any given time.

I think sites like glasshouseworks ( www.glasshouseworks.com/succ-s )and brookside nurseries ( www.brookside-nursery.com/sansevierias ) might be more helpful. I can't understand why The International Sansevieria Society's website doesn't have pictures for ID purposes. Looks like that would be a priority for them.