Even crazier is that Gigabyte offered to repair it for $100, but Newegg refused and later sold it for $500.
You have a broken product. You may have already spent 450$ to get it, but that's sunk cost. You have 3 options:
1. you pay $100 dollars to have a working product (you can sell it for $500).
2. you can engage in fraud and sell this broken product.
3. you write off this loss.
if you discount committing fraud, then the 100$ repair fee definitely makes sense.