Hi,
Hope your "Goal" is a KF. If not turn it to KF by creating a Formula variable(Replacement Path).
I don't see anything wrong with your formula. But just try like below:--
(GOAL < 10000) *10000 + (GOAL >= 10000) * GOAL
or
(GOAL >= 10000) * GOAL + 10000
Regards,
Suman