All MMOs have money sinks so they can tune inflation. The product is not faulty, it's literally by design so the economy doesn't spiral out of control.
One can "disagree" with the design, or not like the design, it's in no way shape or form a "bug". (which is when code doesn't behave the way we intended)
https://en.wikipedia.org/wiki/Gold_sink
Anyway an easy way to remedy high inflation is to increase the supply (improve drop rates). If the market is flooded with manastones, then you won't care if it takes 100 to socket your piece because they'll be fairly low priced.
If you want to remove a money sink out the game, know that what they'll do is just add another that might be even more egregious. And I remember Plumes, bracelets, accessory enchanting, wing enchanting, stigma combining and other nightmares that came later in game... that were all far worse than manastone sinks.
TL:DR yes please increase drop rates