The Maxis Manor has several advantages, but the main one is that you don't have to use Police, Fire Department or Hospital in as big a quadrant of the city. It is worth 1000 SimCash, which is not cheap, but it pays off very well.
The "supposed" second advantage it has is that it sells a Vu product every day, which you can buy for a random price. This is not an advantage, because as you may have read in other Tricks, there are certain days of the week when acquiring Vu items is quite easy, and quite cheaper than the Maxis Manor.
Regardless of this, the second Maxis Manor costs a whopping 2000 SimCash. And here, the acquisition of the second one depends a lot, for example, on how easy it is to win the Contest of Mayors of the Megalopolis league.
What is clear is that the first Maxis Manor is a good idea. From there on, it depends a lot on the gamer, expectations, type of game, etc.