What kind of card is the cheapest for Shandong Mobile to send short messages?

The monthly details of SMS in Shandong M-Zone are as follows: 15 in 1 yuan, 36 in 2 yuan, 6 in 3 yuan and 1, in 5 yuan.

5-minute calls from Bao Fei mobile phone in 2 yuan, M-Zone, Shandong Province are free, and all national mobile phone calls are free.

There are also the following services for users to choose to open:

Talking at night-2 yuan/month, calling .1 yuan every minute from 21: to 8: the next day; 17951IP long-distance toll is free of charge, and only .3 yuan/minute IP call charges are charged

Shenkan Special Zone-2 yuan/month, and the caller in this community is .2 yuan/minute

Thumb School-6 yuan/month, including 15 peer-to-peer messages in the network

Add some color-3 MMS in 6 yuan, 5 MMS in 1 yuan and 1 MMS in 2 yuan.