I don't want to get into a discussion about which thread is "best" because we each have our own opinion. But the topic is cost, and I have read posts here that say Coats and Clark is "expensive." Going by the price at Joann's website, a 500 yard spool of Dual Duty XP polyester is $4.29, or $.0086 a yard. Only two of the examples in the original post were less than that.
Tate