There's a small issue with the 'free' blueprints.
You can only buy the free blueprints providing you have enough cash to actually buy one. If a blueprint costs 200 mil and you have 100 mil, you'll get the error message "cannot spawn blueprint: not enough credits".
It still checks if you have the money but it doesn't deduct the money after purchase, it should not check for your money so you could spawn anything you want without having the money.