Buy physical gift cards from your nearest store and exchange it on bitify/paxful/localbitcoin, but you need to check which ones have the lowest fees and you might find yourself paying even less than 10% with the gift card, just make sure you research all these options before buying the gift cards, there are a lot of ways to buy btc in the US and I am always suprized when people make it look like it's such a huge tusk.