Should 5* basic crystals cost be cut in half
There is not a good reason to pull a 5* basic anymore, and I feel you should pull them completely or drop their price in half. Even if you have an equal number of needed pulls from every class the dual class crystals are a better value. In addition if you stick to the same dual class crystal you will max sig your 5*s of those classes faster leading to more 6* shards.
Reducing the cost of the 5* will keep it as a desired crystal, while maintaining its pool size.