Graveyard Mall offers the Hanes Women's Cotton Wide-Strap Fitted Tank Top 7-Pack in 12 colors for $19.99 with free shipping. That's $2.86 per shirt and among the best prices we've seen for this style. (We saw a 10-pack of these shirts at this price two weeks ago, since expired.) They're available in sizes S to XXL.

Note: These will be shipped in random colors.