This require more organization. otherwise you won't see what you need to see.
I'll order and visualize your data.. from the best to the worst (population/square)
HTML Code:
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Name [Squares] (Pop. - Pop/square) Tokens at max. level = Tokens spent per increasing 1 population/square
>
Settlers Headquarters [2x2] (220 - 55P/s) 241 tokens > (340 - 85P/s) = 8.03 tokens per increasing 1 population/square
Watchtower [2x2] (160 - 40P/s) 137 tokens > (220 - 55P/s) = 9.13 t/ps
Haunted Mansion [2x2] (145 - 36.25P/s) 116 tokens > (205 - 51.25P/s) = 7.73 t/ps
Nord Residence [2x2] (140 - 35P/s) 116 tokens > (200 - 50P/s) = 7.73 t/ps
The frozen manor [2x2] (140 - 35P/s) 116 tokens > (200 - 50P/s) = 7.73 t/ps
Arabian Palace [4x4] (520 - 32.5P/s) 308 tokens > (760 - 47.5P/s) = 20.53 t/ps
Magnificent Residence [4x4] (500 - 31.25P/s) 258 tokens > (720 - 45P/s) = 18.76 t/ps
Oriental tower [2x2] ( 90 - 22.5P/s) 93 tokens > (170 - 42.5P/s) = 4.65 t/ps
Oasis Residence [2x2] (110 - 27.5P/s) 78 tokens > (170 - 42.5P/s) = 5.2 t/ps
Arabian Residence [2x2] (110 - 27.5P/s) 78 tokens > (170 - 42.5P/s) = 5.2 t/ps
Jungle Residence [2x2] (100 - 25P/s) 78 tokens > (160 - 40P/s) = 5.2 t/ps
Witch Tower [2x2] (100 - 25P/s) 78 tokens > (160 - 40P/s) = 5.2 t/ps
Hospitable Bone Church [3x2] (100 - 16.67P/s) 149 tokens > (250 - 41.67P/s) = 5.96 t/ps
White Castle [2x2] ( 50 - 12.5P/s) 79 tokens > (150 - 37.5P/s) = 3.16 t/ps
Pirate Residence [2x2] ( 50 - 12.5P/s) 79 tokens > (150 - 37.5P/s) = 3.16 t/ps
Tipi (4 versions) [2x2] ( 50 - 12.5P/s) 79 tokens > (150 - 37.5P/s) = 3.16 t/ps
Dark Castle [4x4-2] (100 - 7.14P/s) 328 tokens > (650 - 46.425P/s) = 8.14 t/ps
Looks pretty unbalanced in some cases! (Paying less tokens means it's the best choice to spent your tokens)
Edit: Fixed tokens total. my bad lol