This is the problem I have and suspected. Drop rates are low, but it's different. I have always theorized that drop rates are better at higher levels and the threshold seems to be around 55+ as the game rushes you into 50+. However the drop rates in the new low level quest areas seems to be decent (ruins of agony, abandoned camps, gorgon). Comparatively I have farmed just about everywhere up to 50 and it's not just low levels. The new abandoned camps will drop trident left and right now, but farm anywhere else like plains of dion and you get nothing.
I have been agonizing about how to progress because the only players left are 70+ and the only thing being sold now are b grade and up. How is anyone suppose to start on a server when the cheapest items are b grade and will cost you 30mil+. You can't even find c grade anymore. This is sadly why the bot farmers in sea of spores and ivory crater is useful because this is the only place some spellbooks drop and that includes one of the most desired one, deathwhisper. They made changes to the class transfer spellbook, but this is hardly enough when every single player will make their own pp/se and this game is impossible to play unless you box 3-5 accounts MINIMUM because there are only a couple hundred active players and they are all 70+. These spellbooks are still essential and there aren't enough players and there aren't enough players in the level range to adequately farm spellbooks and anything else.
You literally have left no option, but to bot or macro full parties to even progress past 50s. c grade crystals are more expensive then a,b. How ridiculous is that? What are you devs thinking? This game has a very definite progression path and it's player driven. When the only players left are 70s, how are you suppose to even play the game??????
Please JUJI and the devs. You need to consider the 40-50+ range as this level range already starts dropping valuable low/mid c grade stuff that is still useful and even required for progression in a reasonable matter. You leave no option, but to buy adena because drop rates are unreasonably low. I couldn't even farm a BRIGANDINE HELMET. One freaking D armor and it's still impossible!