I've always been able to mail a DVD in those 5" square flat cardboard mailers (that hold the dvd itself with no encasement) for two first class postage stamps.

Recently they got returned for not enough postage. Then I had one weighed at the post office and they said 79 cents. Those also got returned and then when I went to another post office he explain that the other postal worker was mistaken they aren't weighed as regular mail and are charged a different rate like a package.

So the correct amount ended up being $1.34! seemed expensive, I'll have to start building that into what I charge.

The first week in June my extended family had a Reunion in Wrightsville Beach, North Carolina.
I was the lucky boy who ended putting together a photo disk of the event. This past week I mailed
out the first 16 disks.

The cost of mailing, including the box, was $1.85 USD per disk.

In my case the disk was inside a Jewel Case which was itself inside the mailing box.

Part of the additional fee might be due to it being in a square package. For some reason USPS charges more for that than if it's a rectangular one.

I ship my dvd's (in slimline jewel cases) in a padded envelope and put three stamps on it. Never had a return yet.

I ship out disks all the time and I asked this very question to the guy behind the counter. Here is what he said...

It depends on how its classified. If you state that its a disk or if its in a disk mailer then you get bumped up to the higher cost postage (parcel rate vs first class). He said that disks are classified as parcel and don't qualify for the lower standard first class postage due to the fact they are stiff and can't be bent.

His advice:

Package it yourself and put your own postage on it per the first class rate. DO NOT USE A DISK MAILER. Use a standard rectangular padded envelope you can get at the office supply place for about $0.10 each in bulk packages.

He warned...

If its obvious that its a disk you stand a good chance of getting it back with the insufficient postage stamp on it.

Your mileage may vary.. I decided just to pay the parcel rate to ensure I didn't get any disks back.

I use brown manila envelops for Amray cased DVDs. US Postal Service rate for first class mail is $1.68

I do know that it is always cheaper to send it first class rather than media mail. That only seems to come out in favor of heavier books.