Giant Size line will allways be free, though stores might decide to charge or give free with purchase, but stores get em free.
If a given story is a big enough hit it might get pulled from Giant Size line to become its own paid comic.
Basically Giant Size is a way to build an audience for the intelkectual property then rake in the cash off that IP after it gets a massive following. Afterall, most people wont refuse free.
PANCAKES, HOT DOGS, HAMBURGERS and COMICS, they're as popular as APPLE PIE in AMERICA and most stocks connected with those items will bring one great wealth, if invested early imo