Upgrades added: 2,314 Upgrades
After Increasing: + 1,520,000,640,000 Daily Income
Using Betty Calc, I had calculated this:
To upgrade planet from 300,006,720,000 Power to 320,008,320,000 Power.
It would cost 414,176,650,000 Naq to upgrade.
You would need to do 2,315 upgrades.
With the updates, the planet should have simply gone from a 1.5t to a 1.6t planet. I might be doing something completely wrong, if so, I apologise. I did this 3 times, which cost me 6t naq in total. So it would appear, that the updates are running back to previous upgrade costs without the x5 multiplier.