Or maybe change the size of treasury according to the size of a temple?
Starting from the lowest,
Size = Treasury size
(1) = 20 gold
(2) = 40 gold
(3) = 60 gold
(4) = 80 gold
(5) = 100 gold
(6) = 130 gold
(7) = 160 gold
( = 200 gold
(9) = 240 gold
(10) = 300 gold
(11) = 400 gold
(12) = 500 gold
I believe this was done with Secret Societies to limit their use as hidden treasure vaults.