You remember those dungeons and dragons type video games from the 80's? You would fight some sorta beast and then get to open a treasure chest. Think of that chest as your seed. The deeper you went and the bigger the monsters the better the treasure within that chest. Imagine cheap / bag seeds as the first level stuff, fight some harpy or an orc and get a cheap silver treasure, maybe a rusty sword... but those really good beans, the ones you get from the depths of the minotaurs lair after battling a dragon or some shit, those are the beans that can blow your mind, big ass chest of diamonds and the sword of a thousand truths.