Buy two nerdy T-shirts and get one free when you add all three to your cart and use the code B2G1TEE during checkout at ThinkGeek. Shipping adds $8.95. Note that the lowest-priced shirt in your cart drops to free with the code. The promotion includes this Loki Baseball Jersey, which lists at $24.99. It's on sale for $16.97. This women's Spider-Man Patches Lace-Up Top is on sale for the same price. This men's Incredibles Logo Short-Sleeve Shirt falls from $29.99 to $23.97 during the sale. To get the discount, add all three to your cart and use the code to drop the price from $57.91 to $40.94. These styles are only available at ThinkGeek. Sales tax is charged in most states.