Opal was once in Polo and Bittrex, it was listed on Cryptopia somewhere in the summer of 2016.

Further development like new wallets, new roadmap (and maybe masternodes) could mean Opal reaching a few dollars easily

There was actually an article that showed some use case(i don't remember wich country, Netherlands or Denmark) where some dude did some "dirty business" using Opal, there's gotta be a link somewhere in these 200 pages