to be honest , having min costed witches is not a bad ideea , and valks , by the nature of what they are supposed to do , its also good to be as cheap as possible so u can place them early and benefit the most from their UP generation


That being said , i would actually keep on my copies for now if you got the inventory space, that is. In the future it is possible that we will get a new special curency , for which you can trade units. Event units can be traded , but they give pitiful amounts , while premium units give a couple times more.


With said curency , u will be able to buy a powerful Black unit for example. - DMM players can extend of this if they wish.

Ofc , this is speculation , and we don't know how far in the future said upgrade is , but i'd keep the copies for now if i were you.