How To Get Subtotal of Invoice | NetSuite - NSAW - OAC

Greetings Community, I was wondering what's the most efficient manner to show Subtotal from a NetSuite Invoice in NSAW - OAC?

For instance, in this case:

$705 will be shown by using Tax Line = "F" & "To Be Fulfilled = "T", like this:

But I don't believe "To Be Fulfilled" is the most ideal, for example this other Invoice:

uses this Item:

And if I use above logic, it won't show anything because To Be Fulfilled = "F" in this case:

Everything said, would like to know:
1. What's the most ideal way to show Subtotal?
2. I know in NetSuite Transaction Saved Search, we can turn off Shipping Line, isn't there something similar in NSAW - OAC? Which only turns off Shipping Line?