Buying a car from a family member that works at a dealership

I’m looking for opinions on buying a used car from a family member that works at a dealership. My brother in law works for a used car dealer in PA, and it’s one of the no-hassle no-haggle type places that list the car prices on the website and in theory that’s the price they expect people to pay. The make a purecars report available for each vehicle and of course everything they sell falls on the ‘great deal’ side of the of the bell curve.

Unfortunately almost every purecars report I’ve seen seems to be very ‘Dealer Friendly’ in that the purecars value is much higher than the dealer retail you’d see on KBB or Edmunds.

For example the car I’m currently looking at 2007 sebring base 87718 miles. They have it listed for 7500 purecars says that’s 1458 below retail. However Edmunds has the dealer retail set at 6700 for a vehicle in amazing condition.
Is it a good idea buying from a family member that works at a dealership like this (http://ww.devyautopark.com)? Has anyone out there had a similar experience they’d like to share.
(It may also be worth noting that I know he’s personally got a very good reputation in the community and has had a significant number of repeat customers through the years.)