They're not getting paid $300k a year. They're getting paid $160k a year and the delta is made up in RSU. I'm not sure how FB transacts on stocks for you but depending how they deal with the taxes involved OP could be off by a large factor in the net calculation. Also not sure how FB vests stock, but if it's traditional OP still hasn't vested anything (1 year cliff).
It's not traditional actually. We vest quarterly, and I've sold my stock as soon as I've received it (two vest days so far). My third vesting is November 15th.
The last picture gives you my estimated total comp for the year, $343k. It will be something close to that unless $FB has a major change between now and next vesting date in February 2020.