Fry's Electronics has the six-disc "Alien Anthology" for $20 plus free shipping. Pick it up here: http://www.frys.com/product/6405282
Went to the site and it says "In Store Only" no shipping.
And that's advice for any Amazon purchase when the featured seller is "fulfilled by Amazon" rather than sold by them. When Amazon runs out of stock, they often show their price in the "More Buying Choices" section. Amazon already tends to be the cheapest source, but if they ran out because of a great deal, they tend to honor the deal price a bit longer by showing it there. That right hand column is worth looking at, it's also where they call your attention to an item that's a Gold Box deal.
Another great place to check out BDs on sale from Amazon is the blu-ray.com link. I like the deals page because it's so easy to check out pricing history for everything on sale. Just hover over the tiny graph icon. The graph doesn't catch every blowout deal during BF/Cyber weeks, but it's a good place to start. I also like to see what's trending and popular deals (right hand column). When the deals list is long, I can expect to find seasonal deals at my other favorite sellers. The deals page has great sorting features, too.