How much does it cost for the latest full PC version of minecraft if you order it online?

Most country's it's still $26.95 US.

If you keep an eye out for sales (altho rarely) the larger stores like Walmart, Target, etc, do sell it on CD for the same price.

You still need to register an account with a user name and passWord and download the game as the CD only has the launcher/installer.

It only takes around 15 to 20 minutes to download the full game on a slower broadband line.