I believe its the F1* visa you're talking about and there exists an F2 for spouse/dependants. I just had a brief look at some options for training and yeh its a whole lot cheaper. Looks like i can get CPL CFI CFII MEIR and multi engine CFI for around 70k- 80k, AUD whereas in aus this is running >120k.
Also AUD/USD is on the come up on the back of C19 and fed printing, so US training will only get "cheaper".
This looks like a great option, now to decide on california, arizona, florida, nevada or elsewhere for a school...