I am going to attempt here to describe a method of building stable luxury palace blocks. I did not invent this method. I do not know who did. I first saw it used in a game I downloaded from Heavensgames. The game was Londinuim by DET ( posted 4/11/99). I later read a post by Teck in the heavengames forum that covered the same territory. I do know that using this method makes it easy to build an efficient and stable palace block. If anyone can provide me with the linage for this idea, I will be delighted to credit the author here.
The best thing about palaces, as far as I am concerned, is the terrific boost they give to the prosperity rating. Build a block of luxury palaces, and you can almost have the rest of your population sleeping on the streets and still meet your prosperity goals.
If the prosperity requirement is 60+, I consider palaces. If I have limited supplies of some essential commodity, I might want to concentrate those goods in a palace block rather than try to spread them evenly over the whole city. There are also one or two cities which, in the end, you will need the tax income these buildings can provide.
The bad news is that you need EVERYTHING. You name it - oil, furniture, pottery, THREE kinds of food, TWO kinds of wine, plus every entertainment and educational facility known to Roman man.
The good news is that once the markets and houses are stocked, you don't need much of all this stuff. The fact is that 200 patricians living in a building covering 16 squares consume exactly the same amounts of pottery as 20 plebians living in a 1x1 small insulae. Each palace consumes 2 units each of pottery, oil, and furniture per month. For a six unit palace block, that's less than 2 cartloads of each good per year.
You are going to need lots and lots of bodies. Probably about 400 workers to get started, and maybe a couple of hundred more before it's over.
The way I get these workers is: I decide at the beginning of the game if I am going to go for a palace block. If so, I develop lots of housing, but only provide the minimum needed to get it to small casa level. Once there, I hold it there by not providing bathhouses. I keep doing this until I get the workers I need.
OK. Let's start thinking about a place to put these palaces.