Katy Perry -- I Can't Unload This Damn House!

The housing market may be bouncing back for a lot of people, but not Katy Perry, because we've learned she's about to list her Hollywood Hills house for WAY less than the purchase price.

Katy bought the house with Russell Brand when they were married. She has full title and has been quietly trying to sell it for a long time, but she's not getting anywhere near the $8 million she wants.

Katy wanted to avoid putting the house in the multiple listing service -- which is the Paul Revere of the real estate world. She wanted to sell the house on the down-low, but it's just not happening.

We've learned she's agreed to put the house in the MLS in 2 weeks, and she'll reduce the asking price to the mid 7s -- as in millions. But here's the deal ... Our real estate sources say she'll definitely sell it if someone offers in the high 6s.