Sacred Haven of Debauchery

Um... When Valeska arrives, the Citadel will almost certainly place Birds and, with a very high probability, a Monster.

If the Citadel places Monsters at the end of the first or beginning of the second week, then this Citadel probably won't have enough money to buy out the remaining units. Unless it gets very lucky with resources or the game is played on a low difficulty level.