Note that what you want out of that Business travel may mean you’re happy to travel in a more Premium Economy style cabin between Australia & Asia and then fly “proper business” from there. Friends semi-recently bought ”business” seats on a low-cost carrier (can’t recall which … Scoot or AirAsia or similar) between Sydney & Singapore and it was I think around $1k return … you don’t get fancy food or drink, you don’t get a lie-flat seat (but during the day does that matter?), onboard entertainment is bad or not available (they always take their own anyway), and you don’t get lounge access so THIS is where having access can come into play. They have an AmEx which gives them access to AmEx lounges, which aren’t as nice as a First lounge but which apparently are generally OK (you’d have to check for shower access where you were planning to go I think - a shower in the middle of a pair of flights spanning 26hrs is a surprisingly wonderful thing).
They effectively get all the things you want for a Business flight (the comfort & the lounge really - the food & drink are only $50 cafe-meal spec in Business & lounges) but for less than Economy costs on a Qantas or a Singapore Airlines etc etc.
And Business fares are often waaaay cheaper from Asia, to most of the rest of the world, than Australia. I have plans for retirement soon-ish, and my plan is to find daytime flights to/from Asia and maybe spend a few days in those Asian hub-airport cities if different-airline flights don’t line up nicely.
Oh, and to add even more confusion, depending on destination you might research whether there are lounges that have a one-off paid-entry. Credit cards with lounge access or passes, and Priority Pass membership, can be considerably more than one-off entry-fees if you only fly a few times a year.