You won't be able to buy it after the campaign. Either you buy it now, or you buy one used from a backer of the campaign. The Edge is not going to retail, anywhere, after the campaign.
Vine Reviewers seem to be able to make a 10 paragraph review of a printer in under 1 month. It's very common to see them reviewing a different printer each month. When I asked a couple of them about it in the comments, I was quickly attacked by a group of people that are working to become Vine Reviewers. Amazon needs to only allow verified purchasers to review products, or at the very least allow users to hide anything other than a verified review.