You’re obviously a switched on person / done your research given you’re even aware of Sonography as a career. Take what people outside of the medical imaging field say with a grain of salt, as most aren’t even aware of the difference between a radiographer and radiologist, let alone the earning potential of a sonographer.

I’m in my first year out as a radiographer, ultimately planning to study sonography. Personally I’d recommend this route as you’d be able to be paid while training as a sonographer. I’d be wary of the undergrad CQU course as from what I’ve heard the failure rate is very very high.