only if you use a straw

A straw purchase is a purchase that is made on behalf of someone else. An automobile straw purchase made by a person other than the new owner, usually because the new owner has poor credit or is otherwise unable to make the purchase themselves.

it was named

It may harken back to the day when the Israelistes were slaves for the Pharoh and he increased their quota of bricks to make and withheld the important component of straw. I imagine the slaves had to procure the necessary straw through a straw purchase, since they could not purchase the straw for making the bricks. That is my guess until a better one comes along.

Upon researching to find where one can purchase a straw hat it has been found that they are widely available. Straw hats are available at stores such as J. Crew, Roots, The Gap, Gucci and Saks Fifth Avenue.