To determine the total cost of a spell, start with the mana cost or alternative cost you're paying (such as a spectacle cost), add any cost increases, then apply any cost reductions
Magic Foundations Art Series card list & price guide
Invasion of Shandalar / Leyline Surge Invasion of Shandalars effect is a decent enough recursion spell, but if you manage to transform it (and keep Leyline Surge from being destroyed) you can cheat any one permanent in your hand onto the battlefield per turn, which can be absurdly good
Nashi, Moon Sages Scion + Ink-Eyes, Servant of Oni Ninjutsu wont matter if youre using Nashi, Moon Sage's Scion out of the command zone (unless you have a Rule 0 conversation that gives Nashi commander ninjutsu or something)
For those interested in the Duskmourn precons, here's all the essential information about the upcoming Jump Scare deck
If you dont, you may put a land card from your hand onto the battlefield. If you can plot a card, cast something from your graveyard, from exile, from someone elses hand or directly from your deck, you can put something of your choice into play from your hand