Airbnb has to balance the interests of the guests along with the hosts, too much toward either side and Airbnb won't exist much longer. I'm sure there are hosts out there that try to charge guests for normal wear and tear, or who inflate repair costs unreasonably, so to protect guests Airbnb has to ask for quotes. And while asking for multiple quotes may be somewhat of a hardship to a host, doing so provides an extra layer of confidence that the repair costs are reasonable and legitimate, and that it's not the hosts buddy providing an inflated repair quote. I suspect Airbnb only requires multiple quotes when the claim is above a certain amount as I've never had to do that on my claims (but I never had a claim anywhere near $550). BTW, if you're spending $175 to rekey you might want to invest in a Kwikset smart lock to save yourself and your guests some money.