Flying next Friday 10/7 LAX-BKK TG795 and waiting to upgrade to C either with UA miles or cash at the gate. I know UA miles is 35k o/w but if miles can't be worked at the gate, any idea of cash price? I'm holding upgradeable B fares in Y.

As of today there are 9 open seats in C along with several "blocked" seats on our flight. Do those blocked seats get released at the gate? Seems to be the same set blocked on each upcoming flight. Got lucky and somehow two seats opened for upg on our return on 10/22 and I snagged those last week using UA miles.