我不知道这东西值多少钱。

I don't know how much it costs.

youdao

任何一件简单的东西如衬衫，买家或许知道他应该付多少钱，但这并不代表他知道一件衬衫值一般多少钱。

Think about any simple item, like a shirt.A shopper may know how much he or she paid for it, but that doesn't mean the consumer knows how much a shirt, in general, costs.

youdao