The reason they sell for so much is not so much because they are hard to find but instead because 1 water + light = holy water, and that NPC's for about 4000 ~ 4200 a stack.
Light clusters can be found in Upper Delfkutt's tower, sky, qufim island, FeiYin. but the chance of it being light weather in that area is very rare so therefor you will always see the prices for light clusters 3k+
They reason they sell for more is because Light Elementals are hard to find, outside of sky, Qufim is the only place they can be found on a semi-consistent basis. The idea that people would be jacking the price based on AH fees is ludicrous, if that were the case then all items would be selling higher.
For 1k under the price of the stack of light crystalls, you can just use the item and get a Stack of light crystalls and sell them. I dont see the point in cutting the price of the clusters.
