Well, first and foremost, as stated in the "Classifieds" section of this site (which, of course, you can't view yet due to your post count) the 405th does not sell armour.
The reason being due to the many legal/copyright infringements involved with trying to mass-market/mass-produce something of that nature.
We don't have either Microsoft's or Bungie's approval for anything of the sort, and so to try and profit from thier intellectual property could land us in a whole lot of trouble.
It's okay if a few people do that on a case-by-case basis, but if someone were to make a large quantity of them available for immediate sale that'd be greatly frowned upon.
I'm sure a few around here have thought about that, and there are some that even have the knwoledge and skill to do so, but no one in thier right mind would want to risk a hefty fine or imprisonment over this.
Besides, the whole point of this community's existence is for everyone to learn how to make thier own MJOLNIR armour, and later on further improve on it.
To be able to buy a DIY kit sorta takes the fun out of it for a lot of us...