I would take it all down.
You're about to sell your house (part of the earth under dominion of Christ, with you as the vice-regent) and turn it over to some infidel or heretic. And this for a mere $500,000 -- money that you can't take with you.
That is true, and can't be denied.
So are Catholics to never sell any property, because they have consecrated their homes to the Sacred Heart, while most people use homes as hives of sin?
That can't be.
Therefore, I conclude it's OK to sell your house. And it's true that people won't buy a house when it seems like "someone else's house" -- if it's stamped with your personality. It doesn't matter how that is done -- via religious decorations, personal pictures, or anything else.