Need help to understand GST use case

Could anyone help me to understand this use case?

Entity A purchased Computer on 01 Apr 2018 amounting to Rs. 50,000 + GST @ 18% which comes to Rs. 9,000. Later on 01 Jan 2023, Entity A decided to sell the computer for Rs. 20,000 + GST @ 18% which comes to Rs. 3,600. 

• What will be the acceptable transaction value in the above case?