These comparisons are mostly bullshit. Most of them are not comparing costumes, but lighting and background elements in the photos that have nothing to do with the actual costumes. Yeah, some of those handmade ones are clearly superior to the store-bought equivalents. But there is very little difference (and in some cases absolutely no difference) among the Alice in Wonderland, pirate, Link, Adventure Time, Merida and Corpse Bride costumes. Hell, the store-bought PowerPuff Girl masks convey who the cosplayers are supposed to be far more than the hand-made ones, which are just generic dresses.