This question doesn't make sense. "1 kg" is already a unit of measurement (kilogram) and it doesn't have a price.

To make sense of this, you need to ask:

* What does 1 kg *of something* cost? For example:

* "How much does 1 kg of apples cost?"

* "What's the price of 1 kg of gold?"

Please provide more context about what you want to know the price of.