I was at Target (in Omaha) yesterday evening and they have BTTF for only $19.99 for the trilogy on BD. I assume the sale ends Saturday night. It was on a major endcap with some other new releases.
Popular internet rumor has BttF for $14.99 at Target starting Sunday. I cancelled my Amazon order. If Target doesn't have it on Sunday, ten bucks says Amazon matches sometime next week. (Or I can just price match at Best Buy...)
If anyone is wondering about the case type, the one that needs instructions vs one that doesn't apparently you can tell the difference. The better doesn't need instructions on how to get the discs out and there is a 6 or 7 digit number on the lower right side on the back of the outer cover.
Look for the number ending with a 1, the bad packaging ends with a 2.