Transfer KSP to Steam?

[Spacetraindriver]

I bought KSP on the website, way before I started using Steam. I've noticed it and it's DLC (which I do not have) are on sale at the moment and am wondering if its possible to just transfer it over, I guess? Would using the "Add Non-Steam Game to My Library" mean I would not have to purchase the game again? The only answers I've found online have been contradictory. I just need to make sure I'm not wasting anything buying the same game twice when I didn't have to. If I do have to its fine, more money for more updates I guess.  

[Geonovast]

The way the sale is set up right now, you would only save $2.53 buying the DLCs separate from getting the whole bundle.

Personally I would just buy the bundle.

But AFAIK, you can actually buy the DLCs from Steam and then just put the folders into your store install... at least I've seen that mentioned recently on the forum.

Edited July 17, 2019 by Geonovast