Given the popularity of the controller and the number of people who wish to buy one, so it is not surprising that the store is collapsing, while fans around the world are trying to buy the controller, But this one ends up selling.
When loading on the page, delays or viewers are welcomed by a slow ball that never stops stopping, causing potential buyers with what should have been an easy purchase.
If you see that, so do not panic. The site has just been strongly overloaded right now by people trying to get a purchase at the same time. The page has just been put online after all.
Just keep updating the page from time to time and possibly you should be able to buy the device for yourself. Problems should also be temporary, because many people are trying to get the controller at the same time as they worry about his sale.
If all is fine, it should not be a problem, have patience and wait for the site to lose its important influx of buyers and you should be able to get one.