Board Thread:Questions and Answers/@comment-211.203.21.6-20150704051606/@comment-25889587-20150704053648

Opening 6+1 treasure is always better than opening 1 supreme treasure. You are already doing it right, and sorry if you still did not get what you wanted. Everyone has been there as well, including myself.

If you open 1 supreme treasure chest, there's always a possibility that you are going to get an A-rank treasure, while the 6+1 set always give you at least 3 S-rank. In addition, for a total of 119, you can get 7 instead of 6 treasure, which is quite a deal. If you use the traditional way (including the discount if you re-open):

25 + 20 +  20 +  20 +  20 +  20 =  125.

That is 6 more than the 6+1 big set, and you only get 6 treasure (which may turn into all A-rank treasure). In addition, if you opened one big set, you can open another 7 for a 10% discount, into 108. Definitely worth the wait for me.