A few years ago, I purchased five Annual Passes for our use but did so at a significantly reduced rate. I think we bought Premium APs for under $500. Does anyone know if that deal happens regularly and if so, when?
Nothing has been announced. In Fall 2012, DVD offered a special deal, $399 for premium annual pass (less than DVC discounted price for an AP at the time), which needed to be activated by end of 2013. In early 2014, it offered a deal for a PAP at $485 and it needed to be aactivated by January 31, 2015. Many have been hoping for a special deal this year but nothing has happened except for Disney's raising the DVC discount prices over 9% for APs and over 7% for PAP's, while making the discount off the regular price smaller than it was. It thus appears the current Disney plan is to make sure ithe discounted passes cost much more than before rather than creating any special discounts for members.
In response to above the answer is no. You could upgrade to a DVC discounted AP or PAP from a 5 day park hopper, but the specially priced PAP's that were discussed earlier needed to be purchased from MS and were only available for a few months and had deadlines for activation as previously stated