I know that you might not be able to match his US bought model, but at the price that you are quoting, anyone could probably invest a few bucks more and get a new one. Gaming laptops have one of the highest depreciation rates at around 20-25% per year. You need to factor in that when setting an expected price for your 2 year old laptop which is nearly 3 generations old.
As for the 3070 vs 2080 Super comparison, your model has a 2080 Super Max-Q which is much inferior to the non-Max-Q variants. It is slower than the 3070 by 15-20% and slower than the non-MAX-Q variant by 20-25%. So essentially your laptop has the same performance as a 2070S mobile.
Edit: It's being sold brand new on Flipkart for 1.52L
with card offers.