I did a search and was surprised I didn't find this posted yet... I hope my search was thorough. It's not the best deal by any means, but it's still $100 off retail.
Best Buy is discounting 32GB iPhone 7 and iPhone 7+ by $100 to $450 and $570 respectively. Can be an upgrade or a new line. Looks like you have to use a payment plan to get the discount. I'm not sure if paying off early will still get the discount, maybe someone else can chime in.
iPhone 7 https://www.bestbuy.com/site/appl...Id=5580358
iPhone 7+ https://www.bestbuy.com/site/appl...Id=5580424
EDIT: links above are to AT&T versions of the phone but sale applies to Verizon and Sprint as well.