Towns seems ineffective when you have Palaces available

[legowarrior]

I've been enjoying Bronze a lot lately, and I've only played single player so far, but it seems to me, when I play a nation that have both towns at normal cost and palaces, I never (or almost never) bother with the town. I sometimes wait an extra turn to buy a palace in its place (sometimes this is a bad thing). The palace is just really awesome, and for only one point more, I can't resist it. Only in a completely empty area or area with buildings that can't be stolen, does the town even compete with the palace, and in those cases, I'd still rather build a palace, since the building itself can't be stolen, and it could guard future mines embassies, TOWNS or what ever.

So about the rant, I'm just looking for insight into how the costs were decided.