To determine the total cost of a spell, start with the mana cost or alternative cost you’re paying, add any cost increases, then apply any cost reductions. The mana value of the spell remains unchanged, no matter what the total cost to cast it was.

Uthros Psionicist’s ability will count any spells you’ve cast this turn, which may include Uthros Psionicist itself. It doesn’t matter if the other spells resolved, didn’t resolve, were countered, or are still on the stack. If Uthros Psionicist was the first spell you cast this turn, the next spell you cast this turn is your second spell.