UBERhelp1
Viceroy
It may be possible to get a second House without spending diamonds, with some luck. That would be 14 pieces needed, 4 from the quests and then 10 from the minigame. From the last Halloween event I ended up with 12 pieces in total (1 Level 9 Asylum, 1 Level 1 Asylum, and 2 upgrades), where 3 of those came from the questline (meaning 9 from the minigame), so it isn't out of the realm of possibility. If you get (and complete) enough of the side questlines and couple of the bonus tool sets from completing those questlines, it could happen.
By any means, getting a second one with diamonds would be relatively cheap compared to other events since you will end up with a good amount of extra upgrades.
By any means, getting a second one with diamonds would be relatively cheap compared to other events since you will end up with a good amount of extra upgrades.