Take a corsair to 400i warbond for 5$
Then use the store credit during IAE for the rest of the CCU chain.
If that helps I can provide with a Kore/315p to Nomad warbond with LTI (5$ melt) that help you save 10$, Mako to Talon CCU (5$ melt) that help you save 15$, and a Vulture to Taurus (10$...