Man, am I going to miss my Beautiful Dress when the timer runs out on it. My Fortune Pig has already expired and I'm missing those 200 HP. Here soon, I'll be losing another 200 HP.
If it turns out that the PK isn't absolutely horrible and I play the game frequently after level 20, I may invest in a permanent gown of some kind. (They have tons of different fashions, all of which give an extra 200 HP.)