When you quote someone a price, you account for your costs. This includes any tariff or tax you pay. So if Pennsylvania institutes an ohio tariff and I'm quoting a price to Penn, I'm adding up my costs, labor, materials, profit margin, tariffs, shipping, and taxes, then quoting that price to my customer in PA, they're paying it... They might get a lower price from someone within the state, but I'm not eating that cost as a supplier.