Yes. You get Purple chests as drops depending on how much damage you dealt in that raid, which are basically Platinum chests. They're not ALL Magnas/Treasures, but it will still make this:Significantly easier.
Remember, nobody is telling you farm 150+300 fast. Take your time. Eventually, you will get there. Probably long before Purple chest update. Don't your brick on the Guardian.
Oh, and Thunder Rag is getting a huge nerf on x-mas update. They're a massive pain in the butt right now, but will be far more accessible after.