No reliability issues to speak of. Annoyances are similar to the M5 like leaky power steering systems (which has been addressed recently on this car). I've kept the car up to date on maintenance, including Inspection II and valve cover gaskets earlier this year. This one has been exceptionally maintained by previous owners as well so as long as that's continued I see no reason to worry.
Price isn't set since BaT is an auction. There's a reserve but it is reasonable IMO... my guess is it'll sell for less than M5 money by quite a bit.