Back when I bought my original key I did not buy a second.  Is there any way to add a second key for $30 instead of  paying full price again?  I would like to use the second as a backup and a key I can use to play around with Unraid 6.  Thanks in advance!

Yes, and it's valid for whichever version of unRAID you wish to use it with.

 

See here....  http://lime-technology.com/forum/index.php?topic=31474

 

and here...  http://lime-technology.com/second-key

 

Note that you can also upgrade a Plus key to a Pro key for less than the full price of a Pro license.  If you are thinking of doing that you should do so before taking advantage of the extra key for $30

Good point.  Thanks.