Originally Posted by
Kagehitokiri
if economy was expensive, double check F price, may not be that much more
OP doesn't care about which seat he is having. also, he doesn't seems willing to pay $12 extra to choose seat, so checking F price maybe not be the best solution to OP.
as rjw242 pointed out, he is not flying standby, he just need to obtain the seat at the gate.