Could it be the Dritz Mark-B-Gone pens are worth the extra cost? I can remember in the 80's purchasing Mark-B-Gone pens for $.79 from W-Mart. The pens lasted me for 4-6 full size quilts. Now they barely last me one quilt project before drying out. Now they cost $1.67 and are called Mark-B-Gone, by P Rym Sewing. I am not sure what brand they sold at W-Mart back then. Could it have been Dritz? Should I start buying the Dritz pen at $5-$6? Does Dritz brand last longer?