Products are separated into mortal grade, earth grade, sky grade, heavenly grade, spirit grade, celestial grade. They are than further divided into poor, low, medium and high quality.
poor quality spirit stones going for 100,000 credits, low quality spirit stones for 1 million, avg quality spirit stones for 100 million, high quality spirit stones for 1 trillion, and the elusive peak quality spirit stones for 1 quintillion.
Elemental spirit stones start at 10 times the price of normal ones. While unique elemental spirit stones like space or time stones can start at 100 to 1,000 times more than normal ones. Not just for their rarity, but because the space stone is needed for making the transfer gates.