Newegg is selling Lowe’s $100 Gift Cards (Digital Delivery) for $90. That’s a 10% discount. This is a two day sale that expires this Wednesday, 10/18/2017. There’s no promo code required, since discount is already shown on the page. There’s a limit of 1 per account.
At Newegg you also get 3% through Visa SavingsEdge if you have a Visa Business Card such as Chase Ink cards. That will give you a decent discount for personal use, or a very small profit is possible depending on your reselling relationship. You could also try a shopping portal, but I believe they haven’t been tracking recently.