http://www.shipsim.com/downloads/updates
If you download the top two updates, first the one marked "1.3.5" to "1.4" and after that the one marked "1.4.0" to "1.5" You will then have your game fully up to date. As you can see, these are free to download. Once fully up to date all the DLC additions can be bought and safely added to your game. If you have all the updates and DLC's then you do not need to have the Collectors Edition, unless of course you just want to have two versions of the game. Some folks like to have both, but no need at all.
I should point out that the updates are self installing. You can check that they have installed correctly by clicking on "Options" in the start menu. At the lower left of your screen you will see the version and build numbers. I can tell you have the game direct from Vstep, as if it were the Steam version it would have been updated automatically.
Traddles.
