There's another tech that appears now, where your Studies are upgraded to Libraries which produce 2 Tech points each. Plus, there is another structure found down the education tech tree that provides a 50% bonus and occupies 4 squares. No idea if this replaces the School one or not. Finally, Hosten's Library provides a 100% bonus to Tech (only one allowed ingame).
If I remember the weird Stardock jujitsu correctly, these bonuses are multipled by each other (not added together beforehand). So a 50% bonus plus a 100% bonus is really worth 300%, and that 'meager' 25% with Hosten's Library nets a 250% increase. And if you keep both the School and The University in play (i.e. University doesn't replace the School), that's your Library points x 1.25 x 1.5 (or Library points x 1.875), and perhaps double that (3.75) for Hosten's Library if you ended up being able to build it first.
With 50 squares, and specializing in one area (tech), I definitely could see you having 16 Libraries in place when you max out. Plus, if you attach a Lost Library to that city (which produces 5 tech?), that 25% would also apply to the LL (so another 1.25 tech points).
So 16 squares x 1.875 = 30 squares worth, occupying 24 squares.
And if the University replaces the school (instead of being built separately), that's still 16 x 1.5 = 24 square's worth occupying 20 squares.
With Hosten's in place, that's either 60 square's worth occupying 28 squares, or 48 square's worth occupying 24 squares.
So your break even points, square-wise, are:
16 Libraries plus School (20 squares) = 20 Libraries
9 Libraries plus University (only) (13 squares) = 13.5 Libraries
10 Libraries plus School AND University (18 squares) = 18.75 Libraries
5 Libraries plus School AND University AND Hosten's Library (17 squares) = 18.75 Libraries
Or something like that.
