Harry Potter and the Deathly Hallows will be released on April 15th. I am not aware of any coupons for this movie- so here are the current prices:
::BEST BUY.
DVD $13.99
Blu Ray $16.99
Blu Ray +DVD +Bonus Disk $22.99
::TARGET.
DVD $14.99 (you can price match to the Best Buy ad)
Blu Ray + DVD + Digital Copy $22.99DVD Gift Set Years 1-7, part 1 $54.99
Blu Ray Gift Set Years 1-7, part 1 $94.99
::WALMART.
DVD $14.96 and shipping is free!
Blu Ray $16.96 and shipping is free!
Blu Ray+DVD+ Digital Copy $22.96 and shipping is free!
::AMAZON.
DVD $14.99 and shipping is free with Prime/AmazonMom. (Should arrive the day of release)
Blu Ray is priced at $16.99 and shipping is free with Prime/AmazonMom. (Should arrive the day of release.)
Blu Ray + DVD+ Digital Copy $22.99 and shipping is free with Prime/AmazonMom (should arrive the day of release)DVD Gift Set Years 1-7, part 1 $49.99 and shipping is free.
Blu Ray Gift Set Years 1-7, part 1 $89.99
So it looks like everyone is pretty close in price- I would pick the store most convenient for you!

Target has a deal running that if you buy the new Harry Potter movie (any version) and any of the Harry Potter books, then you get a $15 discount making the movie and book $20. Just a suggestion for those Harry Potter fans!
Sorry! I forgot to list the link: http://www.target.com/b/175-9384327-0963431?node=1041598&emseq=32575737&ref=tgt_email_RX104132