How Much For 12 Shirts? I spotted this sign at a shirt shop while on holidays overseas: Prices At A Shirt Shop – How Much For 12 Shirts One shirt costs $25. Two shirts costs $30. Seven shirts costs $100. Buy 10 shirts, get one free. How much should I have to pay for 12 shirts? Readers who viewed this page, also viewed:How To Find Big Prime NumbersFibonacci FlowersTime Travel, Truth and the Color Of My Shirt.