Unhidden Map: Sell or Decipher?

[Eight]

Unhidden Maps are 800k-1m on my server right now. Should I sell or use my map? What are the rewards in the Unhidden Maps, any ideas?

Thanks!

I got one yesterday and it had 10k gil, 300 wind shards, Mariner cotton cloth, and mist silk which I sold for 450k. You can also get the Nutkin minion in the unhidden maps which sell very well if you can get one.