I was in need of a solid support so used (too many) resources on Quistis. I now have her 15 (max)/35 (max)/EX and I am one multi-pull away from the 300 mercy system. Is it worth one more pull to get the extra power stone (plus at this point any weapon I pull is an additional power stone)? Or just save the 5k gems. What is the conventional wisdom when you are one pull away from the next lap of mercy system?