Back when Daemon X Machina was first ported to PC, the early adopters were lucky enough to obtain the free "Prototype Arsenal" DLC set within the first month of release. It was a bonus that not everybody could have and it was a real luxury.
Well, things have changed now as the set has now returned to Steam as a paid DLC and you can get it for roughly $7. The visuals are very basic but they look awesome and if you'd like to see how your pilot would look like in a stripped-down, you will really love this wonderful set.
Marvelous has noted that the Metallic Equipment set (another luxury than only early adopters could have) will still be an exclusive item and they are not planning to sell it in the future. A bummer for that, but understandable.
Daemon X Machina is now available on Nintendo Switch and PC.