Given the mass of toys available the square footage needed for such an endeavor would be significant.
That said I know in Manitoba there are a couple doll museums that have been around for a long time. So why not an action figure museum?
This could work but would certainly be a huge undertaking. It would require enough attractions to get people to come out and get them in the door.
Look at Vulcan, Alberta. It's a similar idea and has been operating for a long time.