I had second thoughts about posting this, as if this IS a bug and it gets fixed, it will actually be to our disadvantage. Still I am basically an honest person so here goes:
I replaced my Breath of Milk aura with Earth Shatterer so I could sell some buildings and buy Kitten Assistants to the RM. Switching auras is supposed to cost "one of the most expensive building"; however in this case it cost me one Chancemaker, which was my highest building but not my most expensive building, that being a Prism. Needless to say I was happy that I lost something that was less expensive to replace, but I wondered if this is how it's supposed to work?