It's very simple actually, NC West is a business, they don't really care about what community says, they speak in numbers, if numbers increasing all good. Clearly a signs that NcWest has this problem for years: numbers going down, player numbers decreasing etc.. encouraging players to make RMT rather then spending in L2 store for a 0.000001% chance of getting something valuable. A lot of players that have invested an significant amount of $ in the game realized that it's better to buy adena from X and buy the item required rather then investing in L2 store/events and have an nonexistent chance on getting the item required. Therefore the $ of the company will decrease as events are not encouraging players to play anymore. So NcWest have 2 options :
1. Encourage players to play events by increasing the change of getting something valuable during events (clearly not an option right @Juji?)
2. Concentrate on statistics and based that x,y,x will invest at least 10k $ in this event making the income of NcWest survive.
Obviously this will not carry on for long, as server dying slowly due to multiple reasons, game mechanics, cheats, RMT, "friendly" GM'S etc.
So yes it's fair to increase prices of items in event, despite this being an unfair treatment to players.
Management of NcWest needs changing ....