The 2x Experience Potion can be purchased from the MOS Market for 500 MOS or 10 for 4200 MOS and has a wiki value of 449,000 coins. It is also the drop item from any of the Gate mobs. Some players also purchase these potions and sell them to other players in the player Market. The player drinking (equipping) a 2x potion begins a 30 minute 2x event for all players in all worlds causing any experience points gained to be doubled including Captcha, Daily Rewards Exp, Party Dungeon Rewards Exp and Kill Quest Rewards Exp. Using more than one potion increases the 2x event timer by 30 minutes each. The following are the personal bonuses given by using a 2x potion - NOTE: These bonuses do not stack.
+15% Accuracy
+15% Strength
+15% Defense
+15% Magic
+15% Woodcutting
+15% Fishing
+15% Cooking
+15% Mining
+15% Archery