They mean $80k for YC VC ($20k each from Yuri Milner, Andreessen Horowitz, General Catalyst, and Maverick Capital) plus the $14-20k from YC itself.
The ~$20k is for 7% (of common stock); the $80k is under START Note terms, essentially convertible debt which inherits the cap/discount of the next note you do. It's conceivable that just means an uncapped note, so adds onto your Series A.
Everyone is offered it; as far as I know everyone has always taken it. I got mine around early July of the summer batch; I assume it's roughly the same still. If you really needed it early I'm sure you could arrange that.
The ~$20k is for 7% (of common stock); the $80k is under START Note terms, essentially convertible debt which inherits the cap/discount of the next note you do. It's conceivable that just means an uncapped note, so adds onto your Series A.