I would think most all would buy the seam ripper or measuring tape. I would look for something different and not as likely to be thought of to swap. Here are a few things that I have given for $5 max exchanges.
http://www.sewunique.com/cf.htm
http://sewtrue.com/Store/Magnetic-Seam-Guide-P442.html
http://clover-usa.com/product/75916/...im_Chaco_Liner