Honestly I did none of the tests as these are just screening tests to find out high or low probability. To really confirm baby's condition more invasive tests are required which have risks of miscarriage. For me, I will not risk miscarriage or consider abortion no matter what the result is/based on probability, hence it is pointless to spend money on the tests imo.
When I was 29 yo, my gynae only asked me to do Oscar. When I was 33, she asked me to do nipt. So I just followed her advice. I just did nipt at 37 but she also did the NT scan for me to check the thickness of the neck and nasal bone/