SCROLLS

Or maybe the demand is lower because people now prefer to put explosive for the 1k+ attack it adds instead of balance and speed.
Just like impendings. They used to be worth over 1M, but now since we have explosives, they are worth not even 200k. It's because people don't really want those anymore. So people need to lower the prices.

Less demand due to hackers, etc and people down-cutting the prices.

Don't blame hackers for you guys' ignorance.
It's not hackers that are doing it, it's the consumers.

For definitive reasons...
Hackers are developers that reverse engineer programming code in order to gain access to, or modify files, test security, etc.
Consumers are the individuals that utilize the hacks that a hacker makes.
There's your difference.

Idiots that undercut each other are the reason that price constantly drop. They feel that (in ignorance) the only way to sell an item is to go lower than the person ahead of them, when in fact I've sold numerous scrolls for more than the person that posted before me in nexons forums simply because I responded to their buyers faster than they did.
It's all a matter of strategy.

By hackers I meant the people that hack (as you said , the ones that utilize the hacks/consumers) . Thank you for clarifying the definition of hacker .

Well , not everyone knows how to use a hack ... I am speaking from experience , in the EU server which is full of consumers , everyone used to sell important items at ridiculously low prices , then complain that they can't make money because the prices are too low , without realising that they are responsible not only for ruining their gameplay , but also other's . Legit players in my opinion , were the ones with advantages . Why ? Cause as a legit player you are happy if you must spend less money then usual on the stuff you need and most probably it's hard to get ...