This is really amazing.
If Fan Tianyu is willing to sell vegetables, then she'll have a steady income as well—7,000 in five days, that's 40,000 in a month, of course, plus or minus whatever, no need to be so precise.
Forty thousand a month, and right now it's September. She could keep supplying veggies until next August before college starts. That's eleven months times forty thousand, so she'd have 440,000. That's enough for a down payment on an apartment in Jiangcheng. When she buys a place, she'll transfer her little brother's household registration over, so he could go to elementary school in Jiangcheng.
After doing the math, Mei Mengzhen was seriously tempted by Tianyu's proposal, but supplying vegetables isn't exactly a walk in the park.
She definitely can't expose her "space", so the problem is: how does she get the veggies out, and how does Fan Tianyu take them?
