The standard of primary school students' custody fee varies according to different regions, service contents and custody institutions. Generally speaking, the expenses of primary school students' custody include meals, snacks, study counseling and activities. The following are some possible cost ranges:

1. Meal fee: If the custodian provides lunch, afternoon tea and dinner, the fee will vary according to the quantity and quality of meals. Generally speaking, the cost of each meal may be between 10-20 yuan.

2. Snack fee: If the custodian provides snacks, the fee will vary according to different regions and types of snacks. Generally speaking, the monthly snack fee may be between 50- 100 yuan.

3. Learning guidance fee: If the custodian provides learning guidance services, the fee will vary according to the theme, duration and content of the guidance. Generally speaking, the tuition fee per hour may be between 50- 100 yuan.

4. Activity fee: If the custodian organizes extracurricular activities, the fee will vary according to the type, frequency and location of the activities. Generally speaking, the cost of each activity may be between 50-200 yuan.

It should be noted that the above fees are for reference only, and the specific fees may vary by region, service content and custodian. When choosing a custodian, parents can choose according to their own needs and budget, and pay attention to the credibility and service quality of the custodian.