Big Sky only has signing bonuses for street captains at the moment, a similar bonus is being offered to BIL captains to move to BOS, as well as a bonus for current FOs to upgrade to captain.
They are hurting for captains in Boston. Many of the current captains have lived in MT for a long time and don't want to have anything to do with the North East.
The 8 new planes are going to BOS and are supposedly fairly new with a GPS and Flight Directors (they won't be old Mesa planes like the others). The planes currently in BOS look like they will be going back to BIL (where they came from).
From what I hear, Big Sky is in court to get out of the Mair contract. Something about no termination date of the contract being illegal. So, Big Sky might not be Mair's to sell in the future. FYI, it is this contract that is limiting the airline to 19 seat planes, so, possibly, when that is over, there is a possibility of larger planes.