100 piece of oysters can earn 50 pieces. According to the relevant information, excluding the cost of ingredients, the cost of hibiscus, peanut oil, pepper, spiced powder, chopped green onion, etc. is about 2 yuan per catty, and the net profit of a catty of small oysters is about 5 yuan. 100 can sell ten kilograms of oysters, so 100 can earn 50 pieces of oysters.