Ive been farming from challenges and buying from the shop for a while, I have enough to zeta 2 skills but Im afraid of doing it and regreting it later. If you dont want to give us more Zetas you could set zome kind of "price" to get the Zetas back from the skill we upgraded in case we dont like it. Maybe set a length of time on which we can "change our mind". I dont know, but something should be done about this. I really want to enjoy some of these new skills, they seem fun as hell but Im afraid of regreting it later and getting behind on the game because of it