Well I haven't done anything like that but I would imagine that you would have to have alot of random Variables and Formula for each thing and for positional because the typically estate game is usually just sprite on a tile map.
Id would look into isometric style tilemap and array and see if you can use them such as this Teh X,Y grid of array can use for storing and placing various estate. and you would have to have each property have their own timer to fire off the money pay-in.
Im thinking you could really benefit from learning [Isometric RPG] because its basically the same thing as what you are making its just instead of exploring and kill things to loot you are using timer and random variable to dynamically engage the player in a living virtual world.
Ok first off forget the art. The Art should be the last thing you should worry about. Start EXTREMELY small im talking about a 2x2 grid map. And experiment the different effect you want to add and write down what worked and what didnt.
Like all RPG its alway up to the developer to design their own variable an effect. Do one thing at a time ask us for a particular effect. Or least Build a list of what you want and how do you envision the game to turn out because there is never one book for everything.
Im willing to help but only on specific part not the whole game since im doing my own as well that isnt an estate lol.