Though as a side note, purchasing the Bands when you're not staying on-site is mostly a convenience factor. You can still reserve FP+ ahead of time, enter the parks and use your FP+ reservations without a Band, all just using the ticket itself. The Bands aren't required for FP+, and if you're not staying on-site you can't use the Band for charging privileges.
Personally I wouldn't buy a Band (though maybe if the right specially-decorated one came out, perhaps...) but I accept that some people see the convenience of the Band as being worth $13.
-Rob