There has been some discussion about the balance of the game So made this table:
|$s||Other cost||VPs||Other benefits||VP per $||$s per VP|
|Palace||$8||Castle||5||crown / prestige||0.625||$1.60|
Unless I am not thinking of this correctly you can see that Follies giving 8/7/6/5 VPs for $10 are the cheapest in the game and Palaces and Castles are close behind.
Now it might make sense to increase the value of the follies to simply make them more sought after. I could only do this alittle because what I do not want is to make getting a Folly a requirement for winning.