Nightmare and hell difficulty are now unlocked by default! Article provides full details:

http://nevergrind.com/blog/top-4-reason ... -100-free/

Yeeeeaaaah, 900 bank slots !!! make it happen and I'll be spending all my crystals on it!
Btw can I get a refund for nightmare/hell so I can buy more bank slots?

Oh and I agree with your move and reasons.

yay, nightmare!
after lvl 70 the exp in normal was kinda slow, maybe i'll get some more lvls in higher difficulty now

Very nice blog post, you brought up several points that I had thought about but didn't bring up in my posts as well. It's clear you thought quite a bit about it.

SO, do we get refunded for the crystals that were spent to unlock them now?

Absolutely not. Think of it as paying for early access!