Normally a trader follows below cycle:
- Pay tax at the time of purchase,
- Collect tax at the time of sale from buyer
You purchased from Gujarat and sold in Rajasthan, in this case you must have paid IGST to Gujarat seller and collected CGST and SGST from local buyer.
You will get input tax credit of IGST paid on purchase.
GST paid on purchase is not cost for you.
Suppose you paid Rs. 100 as IGST and collected CGST and SGST Rs. 110 from buyer. Then you have to pay only Rs. 10 to government after taking input credit of Rs. 100.