In term of Rule 32 of CGST , Supplier of 2Nd hand goods has 2options 1. where the supplier has availed the ITC on inward supply , need to charge GST on Transaction (Sale ) Value 2. Where the supplier has not Avail ITC on his purchases , the value of supply shall be the Difference between the Selling price & Purchase price (Profit)
Note : Above any of option is to be excercise in beginning of FY & need to be continued till end of FY