RWC....help,,,please

MRKIN

Road Worthy Certificate: 这个东西呢，大概的用途是这样的：如果你有一辆车想卖，你必须先去具有资格认证的车行去检查一下你的车况，如果车况不符合要求，你必须要把这些不符合要求的地方进行维修或保养，然后才可以卖掉。如果全部都合格了，车行就给你这个RWC了。同时，只有做完了RWC，Vicroads才给你过户的。我们买车的时候，车主包.

I want to ask, Is it sompulaosy for the seller has to do the RWC before selling the car ? And usually how much is it ?
Because I gave deposit for a car, and I asked the owner about RWC, he doesn't know that...so ..should be not included... what can I do ,??please ....