Vistaprint offers a Custom Printed T-Shirt for $10. Coupon code "VPSHIRT30" cuts the price to $6.99. With $4.99 for shipping, that's tied with last week's mention, $4 off list, and the lowest price we could find. Only front printing is included in the price; additional customization is available for an extra cost. It's available in sizes S to L.
Note that the coupon may automatically apply in-cart.