Arounds70- yes that makes sense and it is an very good question with so many answers
For me it depends if I really LOVE it - how much is the price - do I think I will find it elsewhere- what might I want to make with it later ... I know not much help am I LOL
If it is spendy I will get anywhere from a fat quarter to a yard - if it is a really good price I might buy a couple yards. I have bought "cute" fabric thinking a tote bag , so I get a fat quarter- if I am thinking quilt a yard