Given the ultra-low mileage, I would not expect too much wiggle room on price. I can guarantee that the PPI will uncover a whole slew of suspension issues, and possibly some oil leaks. But that's normal for even well cared for 9 year old X5s. Hopefully not many (potentially expensive) faullts will show up when hooked to the computer.

As far as the accident, more than anything it boils down to the quality of the repair, and the severity. The dealer should be able to give you a general idea of where it was hit...perfect bodywork is incredibly unlikely these days, and there are always tell tale signs. But really good is good enough as long as the damage was cosmetic and not structural.

A lot depends on the demand in your area. In the North East, where most families have at least one SUV, demand for X5s is high. That X5 would go in a wholesale auction for over $12k, and it would be bought without any chance of a complete inspection.

__________________
2014 BMW 328i Xdrive
2011 BMW 335i M-Sport
2008 BMW X5 4.8i Sport
2000 BMW 528i 5sp