Sources connected to the Bieber family says ... Justin wants to make sure his half brother and half sister are living in a really nice home , so he shelled out a cool $850K in cash for a 5-bedroom cabin-style pad in Ontario , where they live with their dad.
We're told ... this isn't a case of the family sponging off Justin ... it's Justin who made the offer to the family .
The house is located way out in the Canadian wilderness in a small town of roughly 8,000 people .
But t's not likely the family is trying to get off the grid ... the family name is plastered right on the mailbox.
