What Happened to the Lancaster's Affordability in Brighton?

The first Lancaster listings have properly dropped and it looks like prices will be/are significantly higher. The 2-BR, 2-BA Penthouse 4, for instance, is asking $800,000 (it's already under contract) and the 1-BR, 2-BA Unit 412 is asking $625,000 (it, too, is under contract). Both of these tags translate out to around $700 a square foot, as does the one for Penthouse 6, a 1-BR that wants $535,000. Is $700 a foot expensive for new construction in Brighton? It is Boston's next It Neighborhood, after all. But still... Right?
· Psst... A Non-Crazy Expensive Condo Coming to Boston [Curbed Boston]
· Brighton Rising: Boston's Next 'It Neighborhood' [Curbed Boston]
· Our What Housing Crisis? archive [Curbed Boston]
[Renderings of one of the model units from the Lancaster's website]