Quoted from jackd104:Marco is over 2x the price
Because they know you need multiple parts from many games and would rather buy from one store instead of multiple stores with multiple shipping charges. Also; Marco usually buys at a price somewhere between wholesale and retail then marks it up to get their profit.
Again; I'm assuming it's because they don't order "wholesale volumes" from these vendors; so don't get economy of scales.
No; I don't have insider knowledge... just spreading rumors I've heard a various places and what happened (by inference) with my Chicago Gun Game sound card.