Is there a significant difference in the quality of cotton in low- to moderately-priced shirts (Gap, BR, H&M, etc.), and pricier blouses, like Anne Fontaine and The Shirt? The Shirt now claims that their cotton is sourced from the same Italian mill that supplies Prada. Does this mean a significant difference in quality, in terms of durability, comfort, breathability, etc.? And if the shirts themselves are cotton-synthetic blend, again, what difference would this make? Basically, is most cotton of the same quality? Thanks!