Awaken summon elemental mana costs

Morphis

I was trying Lilian's reanimator while I wait for better version once I open my pcks(hopefully).

One card ended up being so much better than I thought: ruinous path.
I thought it was very efficient but sometimes could end being slow because of half charge.
On average good.

I was wrong

The awaken effect comes into play so many times Ina a control deck like this one.
In the end it really fits the deck and performs greatly.

So I figured: maybe other awaken are this good, I underestimated the whole thing.
But.... No. Other awaken effects are so much more expensive and for less benefit.

So the question is: why?
How comes a card that is already extremely efficient in itself(5 mana non conditional removal? Sign me up) has the best summon elemental awaken attached to it?(11 mana awaken: summon 6 tokens)

Or I should say... Why other awaken effects have so much higher mana cost?

Some examples:

Boiling Earth16 mana, 4 tokens
Clutch of Currents 12 mana, 3 tokens
Coastal Discovery 12 mana, 4 tokens
Earthen Arms 16 mana, 4 tokens

There are many others...
I can understand some being a little better caus of color/base effect(even if still: ruinous path base effect is great), card rarity or design choice...
But here the difference is between good and "no way anyone will ever use this".

Plastic

Things like this make me feel like the game is rushed, poorly tested and seemingly in alpha phase still. If it's just JC testing these things then I can understand, I guess. If not, then they need to get this stuff wrapped up better.

span_argoman

JC has mentioned this in the forums before. Awaken elemental costs are based on rarity:
Common - 4 mana/elemental
Uncommon - 3 mana/elemental
Rare - 2 mana/elemental

The only thing that changes is the number of elementals for each Awaken spell.

Sinslayer5

The rarity differential makes sense - the question is more a matter of cost versus benefit. I understand wanting to separate the value of certain cards with the mechanic, but at such a wide margin...

Also an extremely useful Awaken spell in a control deck? Rush of Ice.