"That's really inexpensive considering they sell T2 vials for 150cr each, T3 at 250cr each from vendor. They'd have to tweak the recipes a bit more."

There are 3 tiers of vials; they have different potency. The T1 vials should be dirt cheap, because they're crap. There would be different recipes for T2 and T3 vials, which would cost more and require more expensive mats.

I think this is a pretty awesome idea.

The costs for these recipes would have to be fairly expensive. A crate of free T3 curse vials would definitely need to be hard to make. I'm not sure I like the idea of these crates being tradeable. It wouldn't make as much crown/energy circulate as you'd think. As for the Mecha Knight crates. They'd have to be substantially weaker than Mecha Knights found in the clockworks [Maybe a small debuff in attack damage. But there would HAVE to be a major debuff in total health/defense] or perhaps you could make the ingredients for it also hard to find*

Unless the costs are fairly/very expensive [especially for things like mecha knights or perhaps health potions] I don't see this idea going anywhere. It just makes the game much easier than it should be :/

Edit*

@Leviathan: Now I've just read your post again and I noticed that previously I overlooked one, rather essential, part of you idea - the fact that those tanks would be a one-time usable. My eyesight is not as good as it used to be (facepalm).

Sorry for my senseless comment - I really though that tank you suggested would provide knight with vials every time he's going into clockworks (for one-time fee only).

Now, when it eventually occurred to me, that this tanks are one-use only, whole idea sounds really good (well maybe with some minor recipe adjustments). I really endorse it.