By the most conservative reports, we are getting 50m including even the most minimal add-ons. Some claim up to 10m in add-ons, which brings it closer to 60m. All in £ for clarity. Call it evens down the middle at 55m and run with that if it helps you sleep better. Similar with Gabi 45m plus anything from 5m to 10m in add-ons, call it 50m for ease.
I think we will get 50m for Ake as well in one form or another, wouldn't worry about specific numbers as claimed by various outlets, best guesses and a bit of headline generating. The club will be happy with it otherwise it wouldn't be happening. 2.5m at those scales is really neither here nor there to worry about.