Fail every first mission (both red and blue versions), except for 00 and Seed (only the first blue mission). During the Famitsu level you have a random chance of getting to purchase the Weekly Famitsu item for 400 at the shop.
Use Gundam Dynames fifteen times.
Use Heavy Gun and G- Cannon 5 times, with Seabook Arno as the pilot if just using the two MS is not enough...
You need the Gundam Assault Survive Demo save to unlock this bonus.After creating your character.Go to the shop and scroll down to the bottom option ,you will see an item that costs 0G that will give you 250,000G.