Actually, the F/A -18 has a reputation for being a cost-effective fighter compared to other gen 4 fighters.
CC
When we're turning aircraft out at two per month I don't think they're "cost effective" other than by comparison to other aircraft that are also being slowly dragged through the production process.
There really is such a thing as economies of scale and building a few dozen planes a year is a surefire way to guarantee that the aircraft being produced will never benefit from them.
JMHO