The costs you are throwing out are relative to a flat surface like a football field. To contour the turf with humps and bumps, bunker shapes, etc., I think you're looking at closer to $100 million to build a full length golf course. Or more...
The biggest bang for the buck in terms of saving money on maintenance is tees and greens. They are relatively small, are intensely maintained and, especially in the case of tees, can result in an improved product, especially if the existing ones are small or shaded.
There is still a way to go in terms of customer expectation. At my course, we had two tees with artificial turf. Both were too small, and on the north side of hills with tall trees on someone else's land blocking the sun - the tees were dirt. We put in artificial turf and you would think we painted over the Sistine Chapel. Lots of negative comments, one star ratings, you name it. And it's a par 61 executive course. We finally expanded the tees by digging into the hills and building retaining walls at great expense. We still can't grow grass well, but the extra size means there is at least some grass. I personally prefer the turf, but man did we take a lot of heat.