When a player first reaches GE level 4, they usually did so through negotiation, not through fights.
In order to negotiate all encounters of level 4, they will need about 140~150 of each type of goods;
including 10 types in total, 5 current age and 5 previous age.
At that stage, their Tavern Silvers are also usually only barely enough to afford all the "Extra Turns" they need.
Their goods usually can afford the negotiation of GE Level 4 every other week instead of every week.
The players that I know 100% fit this pattern, calculated as follows: 1/1 * 100% = 100%.