The one I use most is my 6'x12'. At least that's the first one that I've worn the markings off of. The templates I use the most are my Marti Michelle ones. LOVE those engineered corners--they make the pieces fit perfectly. But lately I've been using my newest ruler or cutting aid called "Cut-A-Round" for making 1/2 circle double sided Christmas tree
napkins.
As far as the cost, uh....? I don't know. If I want it and have the money for it, I buy it. If I don't have the money I plan it into next month's budget.