I think this stuff is typically quite easy to find these days, but in case someone is looking for it my small local grocery store has 5 or 6 bottles of 2015 BCBS Rare on the shelf. No price listed but when i asked they said $99.95, which i gather is not a great price but less than secondary market.
They also have a small floor stack of 2016 Barleywine at $14.95 a pint.