In wholesale market
buy goods...cheap goods, T1 goods...
may be T2 goods
only buy T3 if u are serious overflow
basically
only buy kp if it is a event quest or alternative of a event quest
this will keep your gold to buy kp cheaper ( this also extend to use resource to buy kp )
keep the rate as low as possible
u need goods to do negotiation .... keeping on production, buying goods and also raise relevant wonder (like the bee)
keep the gold rate low so that u will not be "lock up" in event quests due to super high rate to buy kp with gold even Inno provide alternative route (buy kp ) to bypass a hard event quests