Purchasing the same type of upgrade on the same planet grows progressively more expensive. 1. * Image:Credits icon.png 450, Image:Metal icon.png 150, Image:Crystal icon.png 75 2. * Image:Credits icon.png 550, Image:Metal icon.png 175, Image:Crystal icon.png 125 3. * Image:Credits icon.png 650, Image:Metal icon.png 200, Image:Crystal icon.png 175 4. * Image:Credits icon.png 750, Image:Metal icon.png 225, Image:Crystal icon.png 225