Most of mine 5% gems i found are at the B dungeon run,

Those are very nice stones especially when you start to deal over 1500 in magic attack because 5% of 1500 isdamage to the translations.

I am seeing 5% stones now for 600k in the shops, and Rhombus +48, for 250k, actually the rhombus is cheaper.

most of the people in the shop really don't know how much they worth, so i had been buying the percentage stone for pretty cheap price, because eventually i think the price will go up, once players understand its actual value.