The state of the art bunker system these days is called “Billy Bunker”.
Golf Construction | Better Billy Bunker Inc | United States
It costs about $2-3 a square foot for labor to install plus materials.
A typical bunker is around 1000 sq ft. Sand has been getting VERY expensive.
You would rebuild ALL the bunkers on a course, so 27 a hole championship course would have around 120 bunkers?