Its all about supply and demand. Due to the increased drop rates we are making tons more (so those traditionally stingy about spending money on scrolls will now pay for them). One might argue that the increased drop rate also apply for mobs that drop t1 scroll mats, but the thing is that we get past the levels to get low quality sbl from slimes/lizards/vivis fast, so compared to other factors this creates much more buyers than suppliers. Another thing is nowadays noobs are making so much more from the green drops they simply do not care about selling a stack of 50 scrolls for mere 5 silvers overnight. I've visited Elder these past few days and there are virtually nowhere to buy t1 scrolls. t2 scroll prices jumped from 2s to 10s. There is a very simple way to solve these problems (but I dont want to mentioned it and if you do know please do not mention it as well), since competition is bad........... very bad!!!
