the second one is the most expensive -_- the carpets cost about 200 credits and there are about 56 carpets! So that is 11200 credits :-O then 4400 credits worth of walls, 1000 of walkthrough + door wall, 2750 of green disks, 1400 credits of gumdrop chairs, 500 for a present, 500 for a candy cane, 1000 for the lighted poles, 600 of fences... wow!
that is 23350 credits... didn't know i made that much!
not sure about the other room though...