If you read further, they clarify that's 585k through the end of the year. So factor in a termination package for them and the 585k is less than half of their yearly salary, so they were likely at or above 100k/yr each. Makes a bit more sense.

Unlikely; that's probably the amount they would have spent until they'd have run out of money (in 5 months). They don't have any $40k salaries AFAICT (it's all public). Lowest salary was "junior happiness hero in Manila/Delhi/Hanoi" at $45k: https://open.buffer.com/introducing-open-salaries-at-buffer-...

For half a year, so times two