Premiere APs when to renew

I posted this on DisneyLand page but no response, thought I would try overs here

We have AP for WDW which expire on April 19th (first year having them). We will be in WDW a few weeks before expiration. We have a trip planned for DL in June (5 park days) and tentatively another 2 in WDW in Oct 2015 (4 days) and Dec 2015 (4 days)’ and most likely a Feb or April 2016 trip adding another 8 days. I wanted to get the Premier pass for I think it will be beneficial given the trips this year, my question is should I upgrade in April ( when current AP expires) or let it expire and just buy Premier in June when at DL. I don’t know if the discount (what is the discount can’t find it anywhere) for not letting it expire is worth the extra time (April through June). Hope this ? makes sense.

I don’t think there is any discount on the Premiere at all. Here’s what you need to weigh, is the extra two months at the end when you have nothing planned worth the CA sales tax as opposed to FL?