Yes you get a free Magicband with a AP slider. The math makes since for AP for October, especially since you can get AP room discounts as well, which tend to be about 10 percent more than normal room discounts. If you are staying DVC then that is out of the equation. One thing I would remember though is that The CEO of Disney talked about adding Teir Pricing to Multi Day tickets not just single day as it now is. If you get a AP before then, then you do not have to worry about the Large Price increase in Tickets or even APs.
As for Park Hopper I guess it depends on how you travel. Me and My wife swear by Park Hoppers and take advantage of the Extra Magic Hours for Onsite Guests. For Example Wensdays are the night the Magic Kingdom stays open late. Normally 12pm or 1 am durring the Busy Season. I can get into a different Park say at 8 am if it has a early Morning Magic Hour, and spend 6 hours in that Park, go back to our Room for a nap, grab a bite to Eat and then Be able to be Back in Magic Kingdom by 5pm or 6pm and still have another 6 -8 hours of Park time. Without a Park Hopper, I wouldnt have that ability to take a nap in the mid day and still get 12 hours of Park time.
As a avid Disney fan, I say get the AP as soon as possible, it will be Paid off by the second Trip, After your 4th Trip you can renew your AP Pass with the 100 dollar discount they give for Renewals and still have it for December 19 and December 20th because the Renewal also kicks on your next Visit.