What changed with the Mystery Box Upgrade and Easter 2015 updates?

DrDemagor wrote:
One thing I would like to add is that they also nerfed the blue house farm (and potentially all house farming?) The cost of the house seems to be growing with the number of them you have. Bulding a blue house now costs 216000 for me. While the other houses are still at their low price and those are the ones I only placed once.

Seems like there's an algorithm behind house prices now... the more you build of one, the higher the price gets. The fewer you have, the closer the price is to the "old" price.

So for you, your blue house prices are inflated. For me it's brown houses... others its white houses.