Each week, something will come up for a special price, eg "13 Hours" was previously at USD 19.99, and dropped to 12.99 for a while - almost a week to be exact. Now it's only for Prime Members.
Likewise, "Band of Brothers" is corralled for Prime Members only.
So will it turn back to 'regular'? Yes, but not for the offer price. So if you snooze, you lose :)
Sometimes if something grabs your attention, grab it! Otherwise if it's not really a big deal, wait for the next price drop.