I have done this too, what I believe is happening is that you are only changing the text for the euros and BP and not the actual value itself, because the extra money won't let you buy anything, I tried with under 20k and went to the capsule shop, it wouldn't let me buy anything, what this is doing it just hiding your actual amount of euros, and is totally useless at the moment, however I did find it fun sending a friend a screenshot of a greenie with 1b euros and listening to him freak out :P.