I have also recently had a host tell me they made a mistake in their pricing. I booked for under $400/night and the host tells me they need me to cancel and rebook for $1200/night. I didn't cancel because I would have incurred a fee and possibly a negative rating. The host wasn't willing to negotiate their fee or honor the booking, and ultimately cancelled on me. The property is in a small town and the reservation is for a graduation weekend, so I'm sympathetic knowing they need to make their mortgage. However, now I'm out a rental and am scrambling to find accomodations. AirBnb was unresponsive when I contacted them after the host asked me to cancel or pay for the $1200/night. They originally bumped my email question to a hosting "expert" who was not an AirBnb employee and did not answer my question. When I replied that this was not helpful, I did not receive any response. It wasn't until I received the notice of cancellation that I was given the phone number where I could reach a real AirBnb employee and discuss the issues. I feel like AirBnb hides their contact information until things get really difficult, then they give you the number to reach a real person. I've been both a guest and a host over the years. Not entirely a fan.
