▁of ▁human ▁work ▁in ▁total , ▁including ▁the ▁work ▁of ▁actually ▁making ▁product ▁C . ▁For ▁that ▁reason , ▁most ▁market ▁trade ▁in ▁products ▁is ▁regular ▁and ▁largely ▁predict able ▁as ▁far ▁as ▁price ▁levels ▁are ▁concerned , ▁rather ▁than ▁cha otic ▁and ▁arbitrary . ▁According ▁to ▁Marx , ▁price ▁movements ▁were ▁not ▁simply ▁random , ▁arbitrary ▁or ▁cha otic , ▁but ▁govern ed ▁by ▁caus al ▁laws ▁that ▁limited ▁price ▁vari ability . ▁ ▁The ▁concept ▁of ▁a ▁cost ▁structure ▁refers ▁to ▁the ▁( direct ▁and ▁indirect ) ▁current ▁labour ▁inputs ▁required ▁to ▁make ▁a ▁product , ▁reflected ▁in ▁its ▁price ▁level . ▁The ▁concept ▁of ▁a ▁price ▁structure ▁refers ▁to ▁the ▁fact ▁that ▁prices ▁rarely ▁exist , ▁or ▁change , ▁in ▁isol ation ; ▁instead , ▁price - level s ▁are ▁inter dependent ▁on ▁other ▁price - level s , ▁so ▁that , ▁if ▁some ▁prices ▁would ▁change , ▁a ▁lot ▁of ▁other ▁prices ▁would ▁start ▁to ▁change ▁as ▁well — trans m itting ▁a ▁change ▁in ▁valu ation ▁across ▁the ▁economy . ▁A ▁structure ▁exists ▁if ▁there ▁is ▁a ▁fairly ▁stable ▁relationship ▁across ▁time ▁between ▁price - level s ▁which ▁are ▁inter dependent . ▁Marx ▁arg ues ▁that ▁the ▁cost ▁structures ▁and ▁price ▁structures ▁for ▁products ▁are , ▁in ▁general , ▁determined ▁by ▁the ▁law ▁of ▁value . ▁ ▁Term s ▁of ▁exchange ▁The ▁law ▁of ▁value ▁origin ates ▁in ▁the ▁" ter ms ▁of ▁exchange " ▁established ▁for ▁different ▁products . ▁If ▁a ▁producer ▁has ▁to ▁supply ▁too ▁much