I bet I saved at least $2,000 by practicing approaches on MSFS as an instrument student. The first time I did an NDB approach in the plane (I'd practiced them in MSFS), my CFII was absolutely shocked when I nailed it the first time.

Later when I was instructing, I always recommended its use to my instrument students. Those that used it did significantly better than those that just tried to figure it out in the plane (expensive!).