Silly sannin, you should know better than to accuse a respected member of cheating.
Back to the gem issue, I think thSannin has hit on a good solution about the gem coffers, you could alter it so Sannin rank= Hoshi, Hokage = Gem Coffers, and if there are still a lot of alts at that level, you can raise it even more. If need be it could even be increased to 100 DKs for gem coffers, better that than none at all. Maybe some people actually have the time to raise an alt to sannin, but 4 times as much work would probably put off most people, few people make it that far on their main, to work that hard just for a few dozen gems would be ridiculous.