So you are hypothetically saying 5/1/14? I still think it's worth it if you use it enough.
You save AT LEAST $200 on the renewal pass. Normally the renewal price has been around $415 for me.
I don't remember seeing the difference bee that great. I remember it being around $115 or so but this is from memory.
If you have a pass that expires on Jan 1st of a year and you don't plan to go again until 5/1 of that same year then, even if it's $200, you're buying a pass for 4 months that you won't be using it. That $200 premium may be better put towards the pass extending into the next year (ending on 5/1/2016 instead of 1/1/2016).
You really have to weigh it out based on your use. I'd argue that if you know you're not going to go for 4 months then just hold onto your money and wait.
It's probably best thought of as the difference between, across a 10-year time span to help you figure it out:
1) renewing no matter what: You're ALWAYS going to pay for the annual pass renewal BUT you'll get a discount
2) renewing only when you need it: You're sometimes going to renew at the discount and other times going to pay full price. It depends on how often you go.
I'd bet that, unless you really go each month or something close to that, that you'd probably buy 6-8 APs, granted at variable rates, across the years vs 1 AP at full price and 9 at renewal rates. The cost may come out close to even but with method #2 you're not buying your way into the deal each year but only when you think you'll need it.
In my original example maybe some personal issue comes up and when I expected to go again on 5/1 I couldn't. With renewal I'm already bought in for the year and have spent my money. With waiting my new year doesn't start until I decide AND I still have the money in my pocket for some emergency, if needed. If I give the money to Disney then they have my money without providing any services to me for those however many months (because I can't go on 5/1 and who knows when I'll be back?).