The info is in first post. Assuming they didn't change anything and price goes up by 350 each reset, you need 630k trophies to fully clear first 7 resets. As long as you can get so much trophies, problem is phase 2 is supposed to add few more resets, with their price going up too and costing next 735k trophies - aka total 1365k trophies.

So lets just hope Nutaku did change something and made it so price wont go up after one of resets anymore like it was in previous gacha event.