Solved
STEAM AND ORIGIN, TORN BETWEEN TWO PLATFORMS FOR DLC
O.K. I F*cked up. I bought deluxe mass effect 2 from Steam. Then installed the game, activated cerebrus (or what ever) dlc from within the game. But I couldn't activate collector's weapons and armor...
When you say 'activate' the collector weapon and armor, do you mean they haven't been installed yet?
You can download the DLC from this page (the direct link for the collector gear is here). (Note: While you can download all those DLCs, they will only activate if you're logged into the game with the account they're registered on.)
ME2 on Steam is a bit problematic because the DLC isn't sold there. Apart from the DLC that is included in your package, the only way to even get the DLC for Steam anymore is to buy it from Origin. There used to be a website, but as you pointed out, it's dead.
